Remove RMW interfaces

Signed-off-by: methylDragon <methylDragon@gmail.com>

rclcpp/CMakeLists.txt

@@ -49,6 +49,11 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/detail/rmw_implementation_specific_subscription_payload.cpp
   src/rclcpp/detail/utilities.cpp
   src/rclcpp/duration.cpp
+  src/rclcpp/dynamic_typesupport/dynamic_message.cpp
+  src/rclcpp/dynamic_typesupport/dynamic_message_type.cpp
+  src/rclcpp/dynamic_typesupport/dynamic_message_type_builder.cpp
+  src/rclcpp/dynamic_typesupport/dynamic_message_type_support.cpp
+  src/rclcpp/dynamic_typesupport/dynamic_serialization_support.cpp
   src/rclcpp/event.cpp
   src/rclcpp/exceptions/exceptions.cpp
   src/rclcpp/executable_list.cpp
@@ -95,6 +100,7 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/qos.cpp
   src/rclcpp/event_handler.cpp
   src/rclcpp/qos_overriding_options.cpp
+  src/rclcpp/dynamic_subscription.cpp
   src/rclcpp/serialization.cpp
   src/rclcpp/serialized_message.cpp
   src/rclcpp/service.cpp

rclcpp/include/rclcpp/dynamic_subscription.hpp

@@ -0,0 +1,176 @@
+// Copyright 2022 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_SUBSCRIPTION_HPP_
+#define RCLCPP__DYNAMIC_SUBSCRIPTION_HPP_
+
+#include <rosidl_dynamic_typesupport/identifier.h>
+
+#include <functional>
+#include <memory>
+#include <string>
+
+#include "rcpputils/shared_library.hpp"
+
+#include "rclcpp/callback_group.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type_support.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/node_interfaces/node_topics_interface.hpp"
+#include "rclcpp/qos.hpp"
+#include "rclcpp/serialized_message.hpp"
+#include "rclcpp/subscription_base.hpp"
+#include "rclcpp/typesupport_helpers.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+/// %Subscription for messages whose type descriptions are obtained at runtime.
+/**
+ * Since the type is not known at compile time, this is not a template, and the dynamic library
+ * containing type support information has to be identified and loaded based on the type name.
+ *
+ * NOTE(methylDragon): No considerations for intra-process handling are made.
+ */
+class DynamicSubscription : public rclcpp::SubscriptionBase
+{
+public:
+  // cppcheck-suppress unknownMacro
+  RCLCPP_SMART_PTR_DEFINITIONS(DynamicSubscription)
+
+  template<typename AllocatorT = std::allocator<void>>
+  DynamicSubscription(
+    rclcpp::node_interfaces::NodeBaseInterface * node_base,
+    rclcpp::dynamic_typesupport::DynamicMessageTypeSupport::SharedPtr type_support,
+    const std::string & topic_name,
+    const rclcpp::QoS & qos,
+    std::function<void(
+      rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr,
+      std::shared_ptr<const rosidl_runtime_c__type_description__TypeDescription>
+    )> callback,
+    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options,
+    bool use_take_dynamic_message = true)
+  : SubscriptionBase(
+      node_base,
+      *(type_support->get_rosidl_message_type_support()),
+      topic_name,
+      options.to_rcl_subscription_options(
+        qos),
+      options.event_callbacks,
+      options.use_default_callbacks,
+      use_take_dynamic_message ? SubscriptionType::DYNAMIC_MESSAGE_DIRECT : SubscriptionType::DYNAMIC_MESSAGE_FROM_SERIALIZED),  // NOLINT
+    ts_(type_support),
+    callback_(callback),
+    serialization_support_(nullptr),
+    dynamic_message_(nullptr),
+    dynamic_message_type_(nullptr)
+  {
+    if (!type_support) {
+      throw std::runtime_error("DynamicMessageTypeSupport cannot be nullptr!");
+    }
+
+    if (type_support->get_rosidl_message_type_support()->typesupport_identifier !=
+      rosidl_get_dynamic_typesupport_identifier())
+    {
+      throw std::runtime_error(
+              "DynamicSubscription must use dynamic type introspection type support!");
+    }
+
+    serialization_support_ = type_support->get_shared_dynamic_serialization_support();
+    dynamic_message_type_ = type_support->get_shared_dynamic_message_type()->clone_shared();
+    dynamic_message_ = type_support->get_shared_dynamic_message()->clone_shared();
+  }
+
+  // TODO(methylDragon):
+  /// Deferred type description constructor, only usable if the middleware implementation supports
+  /// type discovery
+
+  RCLCPP_PUBLIC
+  virtual ~DynamicSubscription() = default;
+
+  // Same as create_serialized_message() as the subscription is to serialized_messages only
+  RCLCPP_PUBLIC
+  std::shared_ptr<void> create_message() override;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rclcpp::SerializedMessage> create_serialized_message() override;
+
+  /// Cast the message to a rclcpp::SerializedMessage and call the callback.
+  RCLCPP_PUBLIC
+  void handle_message(
+    std::shared_ptr<void> & message, const rclcpp::MessageInfo & message_info) override;
+
+  /// Handle dispatching rclcpp::SerializedMessage to user callback.
+  RCLCPP_PUBLIC
+  void
+  handle_serialized_message(
+    const std::shared_ptr<rclcpp::SerializedMessage> & serialized_message,
+    const rclcpp::MessageInfo & message_info) override;
+
+  /// This function is currently not implemented.
+  RCLCPP_PUBLIC
+  void handle_loaned_message(
+    void * loaned_message, const rclcpp::MessageInfo & message_info) override;
+
+  // Same as return_serialized_message() as the subscription is to serialized_messages only
+  RCLCPP_PUBLIC
+  void return_message(std::shared_ptr<void> & message) override;
+
+  RCLCPP_PUBLIC
+  void return_serialized_message(std::shared_ptr<rclcpp::SerializedMessage> & message) override;
+
+
+  // DYNAMIC TYPE ==================================================================================
+  // TODO(methylDragon): Reorder later
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr
+  get_shared_dynamic_message_type() override;
+
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr get_shared_dynamic_message() override;
+
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support() override;
+
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr create_dynamic_message() override;
+
+  RCLCPP_PUBLIC
+  void return_dynamic_message(
+    rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message) override;
+
+  RCLCPP_PUBLIC
+  void handle_dynamic_message(
+    const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
+    const rclcpp::MessageInfo & message_info) override;
+
+private:
+  RCLCPP_DISABLE_COPY(DynamicSubscription)
+
+  rclcpp::dynamic_typesupport::DynamicMessageTypeSupport::SharedPtr ts_;
+  std::function<void(
+      rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr,
+      std::shared_ptr<const rosidl_runtime_c__type_description__TypeDescription>
+    )> callback_;
+
+  rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr serialization_support_;
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr dynamic_message_;
+  rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr dynamic_message_type_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DYNAMIC_SUBSCRIPTION_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/detail/dynamic_message_impl.hpp

@@ -0,0 +1,327 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_IMPL_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_IMPL_HPP_
+
+#include <rosidl_dynamic_typesupport/types.h>
+#include <rosidl_dynamic_typesupport/api/dynamic_data.h>
+
+#include <cstdint>
+#include <cstddef>
+#include <memory>
+#include <string>
+
+#include "rclcpp/exceptions.hpp"
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_HPP_
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#endif
+
+
+#define __DYNAMIC_MESSAGE_GET_VALUE_BY_ID_FN(ValueT, FunctionT) \
+  template<> \
+  ValueT \
+  DynamicMessage::get_value<ValueT>(rosidl_dynamic_typesupport_member_id_t id) \
+  { \
+    ValueT out; \
+    rosidl_dynamic_typesupport_dynamic_data_get_ ## FunctionT ## _value( \
+      rosidl_dynamic_data_.get(), id, &out); \
+    return out; \
+  }
+
+#define __DYNAMIC_MESSAGE_GET_VALUE_BY_NAME_FN(ValueT, FunctionT) \
+  template<> \
+  ValueT \
+  DynamicMessage::get_value<ValueT>(const std::string & name) \
+  { \
+    return get_value<ValueT>(get_member_id(name)); \
+  }
+
+#define __DYNAMIC_MESSAGE_SET_VALUE_BY_ID_FN(ValueT, FunctionT) \
+  template<> \
+  void \
+  DynamicMessage::set_value<ValueT>(rosidl_dynamic_typesupport_member_id_t id, ValueT value) \
+  { \
+    rosidl_dynamic_typesupport_dynamic_data_set_ ## FunctionT ## _value( \
+      rosidl_dynamic_data_.get(), id, value); \
+  }
+
+#define __DYNAMIC_MESSAGE_SET_VALUE_BY_NAME_FN(ValueT, FunctionT) \
+  template<> \
+  void \
+  DynamicMessage::set_value<ValueT>(const std::string & name, ValueT value) \
+  { \
+    set_value<ValueT>(get_member_id(name), value); \
+  }
+
+#define __DYNAMIC_MESSAGE_INSERT_VALUE(ValueT, FunctionT) \
+  template<> \
+  rosidl_dynamic_typesupport_member_id_t \
+  DynamicMessage::insert_value<ValueT>(ValueT value) \
+  { \
+    rosidl_dynamic_typesupport_member_id_t out; \
+    rosidl_dynamic_typesupport_dynamic_data_insert_ ## FunctionT ## _value( \
+      rosidl_dynamic_data_.get(), value, &out); \
+    return out; \
+  }
+
+#define DYNAMIC_MESSAGE_DEFINITIONS(ValueT, FunctionT) \
+  __DYNAMIC_MESSAGE_GET_VALUE_BY_ID_FN(ValueT, FunctionT) \
+  __DYNAMIC_MESSAGE_GET_VALUE_BY_NAME_FN(ValueT, FunctionT) \
+  __DYNAMIC_MESSAGE_SET_VALUE_BY_ID_FN(ValueT, FunctionT) \
+  __DYNAMIC_MESSAGE_SET_VALUE_BY_NAME_FN(ValueT, FunctionT) \
+  __DYNAMIC_MESSAGE_INSERT_VALUE(ValueT, FunctionT)
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+/**
+ * Since we're in a ROS layer, these should support all ROS interface C++ types as found in:
+ * https://docs.ros.org/en/rolling/Concepts/About-ROS-Interfaces.html
+ *
+ * Explicitly:
+ * - Basic types:        bool, byte, char
+ * - Float types:        float, double
+ * - Int types:          int8_t, int16_t, int32_t, int64_t
+ * - Unsigned int types: uint8_t, uint16_t, uint32_t, uint64_t
+ * - String types:       std::string, std::u16string
+ */
+
+DYNAMIC_MESSAGE_DEFINITIONS(bool, bool);
+// DYNAMIC_MESSAGE_DEFINITIONS(std::byte, byte);
+DYNAMIC_MESSAGE_DEFINITIONS(char, char);
+DYNAMIC_MESSAGE_DEFINITIONS(float, float32);
+DYNAMIC_MESSAGE_DEFINITIONS(double, float64);
+DYNAMIC_MESSAGE_DEFINITIONS(int8_t, int8);
+DYNAMIC_MESSAGE_DEFINITIONS(int16_t, int16);
+DYNAMIC_MESSAGE_DEFINITIONS(int32_t, int32);
+DYNAMIC_MESSAGE_DEFINITIONS(int64_t, int64);
+DYNAMIC_MESSAGE_DEFINITIONS(uint8_t, uint8);
+DYNAMIC_MESSAGE_DEFINITIONS(uint16_t, uint16);
+DYNAMIC_MESSAGE_DEFINITIONS(uint32_t, uint32);
+DYNAMIC_MESSAGE_DEFINITIONS(uint64_t, uint64);
+// DYNAMIC_MESSAGE_DEFINITIONS(std::string, std::string);
+// DYNAMIC_MESSAGE_DEFINITIONS(std::u16string, std::u16string);
+
+// Byte and String getters have a different implementation and are defined below
+
+
+// BYTE ============================================================================================
+template<>
+std::byte
+DynamicMessage::get_value<std::byte>(rosidl_dynamic_typesupport_member_id_t id)
+{
+  unsigned char out;
+  rosidl_dynamic_typesupport_dynamic_data_get_byte_value(get_rosidl_dynamic_data(), id, &out);
+  return static_cast<std::byte>(out);
+}
+
+
+template<>
+std::byte
+DynamicMessage::get_value<std::byte>(const std::string & name)
+{
+  return get_value<std::byte>(get_member_id(name));
+}
+
+
+template<>
+void
+DynamicMessage::set_value<std::byte>(
+  rosidl_dynamic_typesupport_member_id_t id, const std::byte value)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_byte_value(
+    rosidl_dynamic_data_.get(), id, static_cast<unsigned char>(value));
+}
+
+
+template<>
+void
+DynamicMessage::set_value<std::byte>(const std::string & name, const std::byte value)
+{
+  set_value<std::byte>(get_member_id(name), value);
+}
+
+
+template<>
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_value<std::byte>(const std::byte value)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_byte_value(
+    rosidl_dynamic_data_.get(), static_cast<unsigned char>(value), &out);
+  return out;
+}
+
+
+// STRINGS =========================================================================================
+template<>
+std::string
+DynamicMessage::get_value<std::string>(rosidl_dynamic_typesupport_member_id_t id)
+{
+  size_t buf_length;
+  char * buf = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_string_value(
+    get_rosidl_dynamic_data(), id, &buf, &buf_length);
+  auto out = std::string(buf, buf_length);
+  delete buf;
+  return out;
+}
+
+
+template<>
+std::u16string
+DynamicMessage::get_value<std::u16string>(rosidl_dynamic_typesupport_member_id_t id)
+{
+  size_t buf_length;
+  char16_t * buf = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_wstring_value(
+    get_rosidl_dynamic_data(), id, &buf, &buf_length);
+  auto out = std::u16string(buf, buf_length);
+  delete buf;
+  return out;
+}
+
+
+template<>
+std::string
+DynamicMessage::get_value<std::string>(const std::string & name)
+{
+  return get_value<std::string>(get_member_id(name));
+}
+
+
+template<>
+std::u16string
+DynamicMessage::get_value<std::u16string>(const std::string & name)
+{
+  return get_value<std::u16string>(get_member_id(name));
+}
+
+
+template<>
+void
+DynamicMessage::set_value<std::string>(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string value)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_string_value(
+    rosidl_dynamic_data_.get(), id, value.c_str(), value.size());
+}
+
+
+template<>
+void
+DynamicMessage::set_value<std::u16string>(
+  rosidl_dynamic_typesupport_member_id_t id, const std::u16string value)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_wstring_value(
+    rosidl_dynamic_data_.get(), id, value.c_str(), value.size());
+}
+
+
+template<>
+void
+DynamicMessage::set_value<std::string>(const std::string & name, const std::string value)
+{
+  set_value<std::string>(get_member_id(name), value);
+}
+
+
+template<>
+void
+DynamicMessage::set_value<std::u16string>(const std::string & name, const std::u16string value)
+{
+  set_value<std::u16string>(get_member_id(name), value);
+}
+
+
+template<>
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_value<std::string>(const std::string value)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_string_value(
+    rosidl_dynamic_data_.get(), value.c_str(), value.size(), &out);
+  return out;
+}
+
+
+template<>
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_value<std::u16string>(const std::u16string value)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_wstring_value(
+    rosidl_dynamic_data_.get(), value.c_str(), value.size(), &out);
+  return out;
+}
+
+
+// THROW FOR UNSUPPORTED TYPES =====================================================================
+template<typename ValueT>
+ValueT
+DynamicMessage::get_value(rosidl_dynamic_typesupport_member_id_t id)
+{
+  throw rclcpp::exceptions::UnimplementedError("get_value is not implemented for input type");
+}
+
+
+template<typename ValueT>
+ValueT
+DynamicMessage::get_value(const std::string & name)
+{
+  throw rclcpp::exceptions::UnimplementedError("get_value is not implemented for input type");
+}
+
+
+template<typename ValueT>
+void
+DynamicMessage::set_value(
+  rosidl_dynamic_typesupport_member_id_t id, ValueT value)
+{
+  throw rclcpp::exceptions::UnimplementedError("set_value is not implemented for input type");
+}
+
+
+template<typename ValueT>
+void
+DynamicMessage::set_value(const std::string & name, ValueT value)
+{
+  throw rclcpp::exceptions::UnimplementedError("set_value is not implemented for input type");
+}
+
+
+template<typename ValueT>
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_value(ValueT value)
+{
+  throw rclcpp::exceptions::UnimplementedError("insert_value is not implemented for input type");
+}
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+#undef __DYNAMIC_MESSAGE_GET_VALUE_BY_ID_FN
+#undef __DYNAMIC_MESSAGE_GET_VALUE_BY_NAME_FN
+#undef __DYNAMIC_MESSAGE_SET_VALUE_BY_ID_FN
+#undef __DYNAMIC_MESSAGE_SET_VALUE_BY_NAME_FN
+#undef __DYNAMIC_MESSAGE_INSERT_VALUE
+#undef DYNAMIC_MESSAGE_DEFINITIONS
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_IMPL_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/detail/dynamic_message_type_builder_impl.hpp

@@ -0,0 +1,189 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_TYPE_BUILDER_IMPL_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_TYPE_BUILDER_IMPL_HPP_
+
+#include <rosidl_dynamic_typesupport/types.h>
+#include <rosidl_dynamic_typesupport/api/dynamic_type.h>
+
+#include <cstdint>
+#include <cstddef>
+#include <memory>
+#include <string>
+
+#include "rclcpp/exceptions.hpp"
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_BUILDER_HPP_
+#include "rclcpp/dynamic_typesupport/dynamic_message_type_builder.hpp"
+#endif
+
+
+#define __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_MEMBER_FN(MemberT, FunctionT) \
+  template<> \
+  void \
+  DynamicMessageTypeBuilder::add_member<MemberT>( \
+    rosidl_dynamic_typesupport_member_id_t id, \
+    const std::string & name, \
+    const std::string & default_value) \
+  { \
+    rosidl_dynamic_typesupport_dynamic_type_builder_add_ ## FunctionT ## _member( \
+      rosidl_dynamic_type_builder_.get(), \
+      id, name.c_str(), name.size(), default_value.c_str(), default_value.size()); \
+  }
+
+#define __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_ARRAY_MEMBER_FN(MemberT, FunctionT) \
+  template<> \
+  void \
+  DynamicMessageTypeBuilder::add_array_member<MemberT>( \
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, \
+    size_t array_length, \
+    const std::string & default_value) \
+  { \
+    rosidl_dynamic_typesupport_dynamic_type_builder_add_ ## FunctionT ## _array_member( \
+      rosidl_dynamic_type_builder_.get(), \
+      id, name.c_str(), name.size(), default_value.c_str(), default_value.size(), \
+      array_length); \
+  }
+
+#define __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_UNBOUNDED_SEQUENCE_MEMBER_FN(MemberT, FunctionT) \
+  template<> \
+  void \
+  DynamicMessageTypeBuilder::add_unbounded_sequence_member<MemberT>( \
+    rosidl_dynamic_typesupport_member_id_t id, \
+    const std::string & name, \
+    const std::string & default_value) \
+  { \
+    rosidl_dynamic_typesupport_dynamic_type_builder_add_ ## FunctionT ## \
+    _unbounded_sequence_member( \
+      rosidl_dynamic_type_builder_.get(), \
+      id, name.c_str(), name.size(), default_value.c_str(), default_value.size()); \
+  }
+
+#define __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_BOUNDED_SEQUENCE_MEMBER_FN(MemberT, FunctionT) \
+  template<> \
+  void \
+  DynamicMessageTypeBuilder::add_bounded_sequence_member<MemberT>( \
+    rosidl_dynamic_typesupport_member_id_t id, \
+    const std::string & name, \
+    size_t sequence_bound, \
+    const std::string & default_value) \
+  { \
+    rosidl_dynamic_typesupport_dynamic_type_builder_add_ ## FunctionT ## _bounded_sequence_member( \
+      rosidl_dynamic_type_builder_.get(), \
+      id, name.c_str(), name.size(), default_value.c_str(), default_value.size(), \
+      sequence_bound); \
+  }
+
+#define DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(MemberT, FunctionT) \
+  __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_MEMBER_FN(MemberT, FunctionT) \
+  __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_ARRAY_MEMBER_FN(MemberT, FunctionT) \
+  __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_UNBOUNDED_SEQUENCE_MEMBER_FN(MemberT, FunctionT) \
+  __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_BOUNDED_SEQUENCE_MEMBER_FN(MemberT, FunctionT) \
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+/**
+ * Since we're in a ROS layer, these should support all ROS interface C++ types as found in:
+ * https://docs.ros.org/en/rolling/Concepts/About-ROS-Interfaces.html
+ *
+ * Explicitly:
+ * - Basic types:        bool, byte, char
+ * - Float types:        float, double
+ * - Int types:          int8_t, int16_t, int32_t, int64_t
+ * - Unsigned int types: uint8_t, uint16_t, uint32_t, uint64_t
+ * - String types:       std::string, std::u16string
+ */
+
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(bool, bool);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(std::byte, byte);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(char, char);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(float, float32);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(double, float64);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(int8_t, int8);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(int16_t, int16);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(int32_t, int32);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(int64_t, int64);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(uint8_t, uint8);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(uint16_t, uint16);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(uint32_t, uint32);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(uint64_t, uint64);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(std::string, string);
+DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS(std::u16string, wstring);
+
+
+// THROW FOR UNSUPPORTED TYPES =====================================================================
+template<typename MemberT>
+void
+DynamicMessageTypeBuilder::add_member(
+  rosidl_dynamic_typesupport_member_id_t id,
+  const std::string & name,
+  const std::string & default_value)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "add_member is not implemented for input type");
+}
+
+
+template<typename MemberT>
+void
+DynamicMessageTypeBuilder::add_array_member(
+  rosidl_dynamic_typesupport_member_id_t id,
+  const std::string & name,
+  size_t array_length, const std::string & default_value)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "add_array_member is not implemented for input type");
+}
+
+
+template<typename MemberT>
+void
+DynamicMessageTypeBuilder::add_unbounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id,
+  const std::string & name,
+  const std::string & default_value)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "add_unbounded_sequence_member is not implemented for input type");
+}
+
+
+template<typename MemberT>
+void
+DynamicMessageTypeBuilder::add_bounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id,
+  const std::string & name,
+  size_t sequence_bound,
+  const std::string & default_value)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "add_bounded_sequence_member is not implemented for input type");
+}
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+#undef __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_MEMBER_FN
+#undef __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_ARRAY_MEMBER_FN
+#undef __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_UNBOUNDED_SEQUENCE_MEMBER_FN
+#undef __DYNAMIC_MESSAGE_TYPE_BUILDER_ADD_BOUNDED_SEQUENCE_MEMBER_FN
+#undef DYNAMIC_MESSAGE_TYPE_BUILDER_DEFINITIONS
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_TYPE_BUILDER_IMPL_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/dynamic_message.hpp

@@ -0,0 +1,430 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_HPP_
+
+#include <rcl/types.h>
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+
+class DynamicMessageType;
+class DynamicMessageTypeBuilder;
+
+/// Utility wrapper class for rosidl_dynamic_typesupport_dynamic_data_t *
+/**
+ * This class:
+ * - Manages the lifetime of the raw pointer.
+ * - Exposes getter methods to get the raw pointer and shared pointers
+ * - Exposes the underlying serialization support API
+ *
+ * Ownership:
+ * - This class borrows the rosidl_dynamic_typesupport_serialization_support_t stored in the passed
+ *   DynamicSerializationSupport. So it cannot outlive the DynamicSerializationSupport.
+ * - The DynamicSerializationSupport's rosidl_dynamic_typesupport_serialization_support_t pointer
+ *   must point to the same location in memory as the stored raw pointer!
+ *
+ * Note: This class is meant to map to the lower level rosidl_dynamic_typesupport_dynamic_data_t,
+ *       even though rosidl_dynamic_typesupport_dynamic_data_t is equivalent to
+ *       rosidl_dynamic_typesupport_dynamic_data_t, exposing the fundamental methods available to
+ *       rosidl_dynamic_typesupport_dynamic_data_t, allowing the user to access the data's fields.
+ */
+class DynamicMessage : public std::enable_shared_from_this<DynamicMessage>
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(DynamicMessage)
+
+  // CONSTRUCTION ==================================================================================
+  // Most constructors require a passed in DynamicSerializationSupport::SharedPtr, to extend the
+  // lifetime of the serialization support (if the constructor cannot otherwise get it from args).
+  //
+  // In cases where a dynamic data pointer is passed, the serialization support composed by
+  // the data should be the exact same object managed by the DynamicSerializationSupport,
+  // otherwise the lifetime management will not work properly.
+
+  /// Construct a new DynamicMessage with the provided dynamic type builder
+  RCLCPP_PUBLIC
+  explicit DynamicMessage(std::shared_ptr<DynamicMessageTypeBuilder> dynamic_type_builder);
+
+  /// Construct a new DynamicMessage with the provided dynamic type
+  RCLCPP_PUBLIC
+  explicit DynamicMessage(std::shared_ptr<DynamicMessageType> dynamic_type);
+
+  /// Assume ownership of raw pointer
+  RCLCPP_PUBLIC
+  DynamicMessage(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data);
+
+  /// Copy shared pointer
+  RCLCPP_PUBLIC
+  DynamicMessage(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t> rosidl_dynamic_data);
+
+  /// Loaning constructor
+  /// Must only be called with raw ptr obtained from loaning!
+  // NOTE(methylDragon): I'd put this in protected, but I need this exposed to
+  //                     enable_shared_from_this...
+  RCLCPP_PUBLIC
+  DynamicMessage(
+    DynamicMessage::SharedPtr parent_data,
+    rosidl_dynamic_typesupport_dynamic_data_t * rosidl_loaned_data);
+
+  // NOTE(methylDragon): Deliberately no constructor from description to nudge users towards using
+  //                     construction from dynamic type/builder, which is more efficient
+
+  /// Copy constructor
+  RCLCPP_PUBLIC
+  DynamicMessage(const DynamicMessage & other);
+
+  /// Move constructor
+  RCLCPP_PUBLIC
+  DynamicMessage(DynamicMessage && other) noexcept;
+
+  /// Copy assignment
+  RCLCPP_PUBLIC
+  DynamicMessage & operator=(const DynamicMessage & other);
+
+  /// Move assignment
+  RCLCPP_PUBLIC
+  DynamicMessage & operator=(DynamicMessage && other) noexcept;
+
+  RCLCPP_PUBLIC
+  virtual ~DynamicMessage();
+
+
+  // GETTERS =======================================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_library_identifier() const;
+
+  RCLCPP_PUBLIC
+  const std::string
+  get_name() const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_dynamic_data_t *
+  get_rosidl_dynamic_data();
+
+  RCLCPP_PUBLIC
+  const rosidl_dynamic_typesupport_dynamic_data_t *
+  get_rosidl_dynamic_data() const;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t>
+  get_shared_rosidl_dynamic_data();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<const rosidl_dynamic_typesupport_dynamic_data_t>
+  get_shared_rosidl_dynamic_data() const;
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support();
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::ConstSharedPtr
+  get_shared_dynamic_serialization_support() const;
+
+  RCLCPP_PUBLIC
+  size_t
+  get_item_count() const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  get_member_id(size_t index) const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  get_member_id(const std::string & name) const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  get_array_index(size_t index) const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  get_array_index(const std::string & name) const;
+
+
+  // METHODS =======================================================================================
+  RCLCPP_PUBLIC
+  DynamicMessage
+  clone() const;
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  clone_shared() const;
+
+  RCLCPP_PUBLIC
+  DynamicMessage
+  init_from_type(DynamicMessageType & type) const;
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  init_from_type_shared(DynamicMessageType & type) const;
+
+  RCLCPP_PUBLIC
+  bool
+  equals(const DynamicMessage & other) const;
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  loan_value(rosidl_dynamic_typesupport_member_id_t id);
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  loan_value(const std::string & name);
+
+  RCLCPP_PUBLIC
+  void
+  clear_all_values();
+
+  RCLCPP_PUBLIC
+  void
+  clear_nonkey_values();
+
+  RCLCPP_PUBLIC
+  void
+  clear_value(rosidl_dynamic_typesupport_member_id_t id);
+
+  RCLCPP_PUBLIC
+  void
+  clear_value(const std::string & name);
+
+  RCLCPP_PUBLIC
+  void
+  clear_sequence();
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_sequence_data();
+
+  RCLCPP_PUBLIC
+  void
+  remove_sequence_data(rosidl_dynamic_typesupport_member_id_t index);
+
+  RCLCPP_PUBLIC
+  bool
+  serialize(rcl_serialized_message_t * buffer);
+
+  RCLCPP_PUBLIC
+  bool
+  deserialize(rcl_serialized_message_t * buffer);
+
+
+  // MEMBER ACCESS TEMPLATES =======================================================================
+  /**
+   * Since we're in a ROS layer, these should support all ROS interface C++ types as found in:
+   * https://docs.ros.org/en/rolling/Concepts/About-ROS-Interfaces.html
+   *
+   * Explicitly:
+   * - Basic types:        bool, byte, char
+   * - Float types:        float, double
+   * - Int types:          int8_t, int16_t, int32_t, int64_t
+   * - Unsigned int types: uint8_t, uint16_t, uint32_t, uint64_t
+   * - String types:       std::string, std::u16string
+   */
+
+  template<typename ValueT>
+  ValueT
+  get_value(rosidl_dynamic_typesupport_member_id_t id);
+
+  template<typename ValueT>
+  ValueT
+  get_value(const std::string & name);
+
+  template<typename ValueT>
+  void
+  set_value(rosidl_dynamic_typesupport_member_id_t id, ValueT value);
+
+  template<typename ValueT>
+  void
+  set_value(const std::string & name, ValueT value);
+
+  template<typename ValueT>
+  rosidl_dynamic_typesupport_member_id_t
+  insert_value(ValueT value);
+
+
+  // FIXED STRING MEMBER ACCESS ====================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_fixed_string_value(rosidl_dynamic_typesupport_member_id_t id, size_t string_length);
+
+  RCLCPP_PUBLIC
+  const std::string
+  get_fixed_string_value(const std::string & name, size_t string_length);
+
+  RCLCPP_PUBLIC
+  const std::u16string
+  get_fixed_wstring_value(rosidl_dynamic_typesupport_member_id_t id, size_t wstring_length);
+
+  RCLCPP_PUBLIC
+  const std::u16string
+  get_fixed_wstring_value(const std::string & name, size_t wstring_length);
+
+  RCLCPP_PUBLIC
+  void
+  set_fixed_string_value(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string value, size_t string_length);
+
+  RCLCPP_PUBLIC
+  void
+  set_fixed_string_value(const std::string & name, const std::string value, size_t string_length);
+
+  RCLCPP_PUBLIC
+  void
+  set_fixed_wstring_value(
+    rosidl_dynamic_typesupport_member_id_t id, const std::u16string value, size_t wstring_length);
+
+  RCLCPP_PUBLIC
+  void
+  set_fixed_wstring_value(
+    const std::string & name, const std::u16string value, size_t wstring_length);
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_fixed_string_value(const std::string value, size_t string_length);
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_fixed_wstring_value(const std::u16string value, size_t wstring_length);
+
+
+  // BOUNDED STRING MEMBER ACCESS ==================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_bounded_string_value(rosidl_dynamic_typesupport_member_id_t id, size_t string_bound);
+
+  RCLCPP_PUBLIC
+  const std::string
+  get_bounded_string_value(const std::string & name, size_t string_bound);
+
+  RCLCPP_PUBLIC
+  const std::u16string
+  get_bounded_wstring_value(rosidl_dynamic_typesupport_member_id_t id, size_t wstring_bound);
+
+  RCLCPP_PUBLIC
+  const std::u16string
+  get_bounded_wstring_value(const std::string & name, size_t wstring_bound);
+
+  RCLCPP_PUBLIC
+  void
+  set_bounded_string_value(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string value, size_t string_bound);
+
+  RCLCPP_PUBLIC
+  void
+  set_bounded_string_value(const std::string & name, const std::string value, size_t string_bound);
+
+  RCLCPP_PUBLIC
+  void
+  set_bounded_wstring_value(
+    rosidl_dynamic_typesupport_member_id_t id, const std::u16string value, size_t wstring_bound);
+
+  RCLCPP_PUBLIC
+  void
+  set_bounded_wstring_value(
+    const std::string & name, const std::u16string value, size_t wstring_bound);
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_bounded_string_value(const std::string value, size_t string_bound);
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_bounded_wstring_value(const std::u16string value, size_t wstring_bound);
+
+
+  // NESTED MEMBER ACCESS ==========================================================================
+  RCLCPP_PUBLIC
+  DynamicMessage
+  get_complex_value(rosidl_dynamic_typesupport_member_id_t id);
+
+  RCLCPP_PUBLIC
+  DynamicMessage
+  get_complex_value(const std::string & name);
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  get_complex_value_shared(rosidl_dynamic_typesupport_member_id_t id);
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  get_complex_value_shared(const std::string & name);
+
+  RCLCPP_PUBLIC
+  void
+  set_complex_value(rosidl_dynamic_typesupport_member_id_t id, DynamicMessage & value);
+
+  RCLCPP_PUBLIC
+  void
+  set_complex_value(const std::string & name, DynamicMessage & value);
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_complex_value_copy(const DynamicMessage & value);
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_member_id_t
+  insert_complex_value(DynamicMessage & value);
+
+protected:
+  // NOTE(methylDragon):
+  // This is just here to extend the lifetime of the serialization support
+  // It isn't actually used by the builder since the builder should compose its own support
+  //
+  // ... Though ideally it should be the exact same support as the one stored in the
+  // DynamicSerializationSupport
+  DynamicSerializationSupport::SharedPtr serialization_support_;
+
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t> rosidl_dynamic_data_;
+
+  bool is_loaned_;
+
+  // Used for returning the loaned value, and lifetime management
+  DynamicMessage::SharedPtr parent_data_;
+
+private:
+  RCLCPP_PUBLIC
+  DynamicMessage();
+
+  RCLCPP_PUBLIC
+  bool
+  match_serialization_support_(
+    const DynamicSerializationSupport & serialization_support,
+    const rosidl_dynamic_typesupport_dynamic_data_t & dynamic_data);
+};
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/dynamic_message_type.hpp

@@ -0,0 +1,207 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_HPP_
+
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+
+class DynamicMessage;
+class DynamicMessageTypeBuilder;
+
+/// Utility wrapper class for `rosidl_dynamic_typesupport_dynamic_type_t *`
+/**
+ * This class:
+ * - Manages the lifetime of the raw pointer.
+ * - Exposes getter methods to get the raw pointer and shared pointers
+ * - Exposes the underlying serialization support API
+ *
+ * Ownership:
+ * - This class borrows the `rosidl_dynamic_typesupport_serialization_support_t` stored in the
+ *   passed `DynamicSerializationSupport`.
+ *   So it cannot outlive the `DynamicSerializationSupport`.
+ * - The `DynamicSerializationSupport`'s `rosidl_dynamic_typesupport_serialization_support_t`
+ *   pointer must point to the same location in memory as the stored raw pointer!
+ *
+ * This class is meant to map to the lower level `rosidl_dynamic_typesupport_dynamic_type_t`,
+ * which can be constructed via `DynamicMessageTypeBuilder`, which maps to
+ * `rosidl_dynamic_typesupport_dynamic_type_builder_t`.
+ *
+ *  The usual method of obtaining a `DynamicMessageType` is through construction of
+ *  `rosidl_message_type_support_t` via `rcl_dynamic_message_type_support_handle_create()`, then
+ *  taking ownership of its contents. But `DynamicMessageTypeBuilder` can also be used to obtain
+ *  `DynamicMessageType` by constructing it bottom-up instead, since it exposes the lower_level
+ *  rosidl methods.
+ */
+class DynamicMessageType : public std::enable_shared_from_this<DynamicMessageType>
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(DynamicMessageType)
+
+  // CONSTRUCTION ==================================================================================
+  // Most constructors require a passed in `DynamicSerializationSupport::SharedPtr`, to extend the
+  // lifetime of the serialization support (if the constructor cannot otherwise get it from args).
+  //
+  // In cases where a dynamic type pointer is passed, the serialization support composed by
+  // the type should be the exact same object managed by the `DynamicSerializationSupport`,
+  // otherwise the lifetime management will not work properly.
+
+  /// Construct a new `DynamicMessageType` with the provided dynamic type builder
+  RCLCPP_PUBLIC
+  explicit DynamicMessageType(std::shared_ptr<DynamicMessageTypeBuilder> dynamic_type_builder);
+
+  /// Assume ownership of raw pointer
+  RCLCPP_PUBLIC
+  DynamicMessageType(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type);
+
+  /// Copy shared pointer
+  RCLCPP_PUBLIC
+  DynamicMessageType(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t> rosidl_dynamic_type);
+
+  /// From description
+  RCLCPP_PUBLIC
+  DynamicMessageType(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    const rosidl_runtime_c__type_description__TypeDescription & description);
+
+  /// Copy constructor
+  RCLCPP_PUBLIC
+  DynamicMessageType(const DynamicMessageType & other);
+
+  /// Move constructor
+  RCLCPP_PUBLIC
+  DynamicMessageType(DynamicMessageType && other) noexcept;
+
+  /// Copy assignment
+  RCLCPP_PUBLIC
+  DynamicMessageType & operator=(const DynamicMessageType & other);
+
+  /// Move assignment
+  RCLCPP_PUBLIC
+  DynamicMessageType & operator=(DynamicMessageType && other) noexcept;
+
+  RCLCPP_PUBLIC
+  virtual ~DynamicMessageType();
+
+  /// Swaps the serialization support if `serialization_support` is populated
+  RCLCPP_PUBLIC
+  void
+  init_from_description(
+    const rosidl_runtime_c__type_description__TypeDescription & description,
+    DynamicSerializationSupport::SharedPtr serialization_support = nullptr);
+
+  // GETTERS =======================================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_library_identifier() const;
+
+  RCLCPP_PUBLIC
+  const std::string
+  get_name() const;
+
+  RCLCPP_PUBLIC
+  size_t
+  get_member_count() const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_dynamic_type_t *
+  get_rosidl_dynamic_type();
+
+  RCLCPP_PUBLIC
+  const rosidl_dynamic_typesupport_dynamic_type_t *
+  get_rosidl_dynamic_type() const;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t>
+  get_shared_rosidl_dynamic_type();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<const rosidl_dynamic_typesupport_dynamic_type_t>
+  get_shared_rosidl_dynamic_type() const;
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support();
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::ConstSharedPtr
+  get_shared_dynamic_serialization_support() const;
+
+
+  // METHODS =======================================================================================
+  RCLCPP_PUBLIC
+  DynamicMessageType
+  clone() const;
+
+  RCLCPP_PUBLIC
+  DynamicMessageType::SharedPtr
+  clone_shared() const;
+
+  RCLCPP_PUBLIC
+  bool
+  equals(const DynamicMessageType & other) const;
+
+  RCLCPP_PUBLIC
+  DynamicMessage
+  build_dynamic_message();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<DynamicMessage>
+  build_dynamic_message_shared();
+
+protected:
+  // NOTE(methylDragon):
+  // This is just here to extend the lifetime of the serialization support
+  // It isn't actually used by the builder since the builder should compose its own support
+  //
+  // ... Though ideally it should be the exact same support as the one stored in the
+  // `DynamicSerializationSupport`
+  DynamicSerializationSupport::SharedPtr serialization_support_;
+
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t> rosidl_dynamic_type_;
+
+private:
+  RCLCPP_PUBLIC
+  DynamicMessageType();
+
+  RCLCPP_PUBLIC
+  bool
+  match_serialization_support_(
+    const DynamicSerializationSupport & serialization_support,
+    const rosidl_dynamic_typesupport_dynamic_type_t & rosidl_dynamic_type);
+};
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/dynamic_message_type_builder.hpp

@@ -0,0 +1,414 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_BUILDER_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_BUILDER_HPP_
+
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+class DynamicMessage;
+class DynamicMessageType;
+
+/// Utility wrapper class for `rosidl_dynamic_typesupport_dynamic_type_builder_t *`
+/**
+ * This class:
+ * - Manages the lifetime of the raw pointer.
+ * - Exposes getter methods to get the raw pointer and shared pointers
+ * - Exposes the underlying serialization support API
+ *
+ * Ownership:
+ * - This class borrows the rosidl_dynamic_typesupport_serialization_support_t stored in the passed
+ *   `DynamicSerializationSupport`.
+ *   So it cannot outlive the `DynamicSerializationSupport`.
+ * - The `DynamicSerializationSupport`'s `rosidl_dynamic_typesupport_serialization_support_t`
+ *   pointer must point to the same location in memory as the stored raw pointer!
+ *
+ * This class is meant to map to rosidl_dynamic_typesupport_dynamic_type_builder_t, facilitating the
+ * construction of dynamic types bottom-up in the C++ layer.
+ *
+ * The usual method of obtaining a `DynamicMessageType` is through construction of
+ * `rosidl_message_type_support_t` via `rcl_dynamic_message_type_support_handle_create()`, then
+ * taking ownership of its contents.
+ * But `DynamicMessageTypeBuilder` can also be used to obtain `DynamicMessageType` by constructing
+ * it bottom-up instead, since it exposes the lower_level rosidl methods.
+ */
+class DynamicMessageTypeBuilder : public std::enable_shared_from_this<DynamicMessageTypeBuilder>
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(DynamicMessageTypeBuilder)
+
+  // CONSTRUCTION ==================================================================================
+  // All constructors require a passed in `DynamicSerializationSupport::SharedPtr`, to extend the
+  // lifetime of the serialization support.
+  //
+  // In cases where a dynamic type builder pointer is passed, the serialization support composed by
+  // the builder should be the exact same object managed by the `DynamicSerializationSupport`,
+  // otherwise the lifetime management will not work properly.
+
+  /// Construct a new `DynamicMessageTypeBuilder` with the provided serialization support
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    const std::string & name);
+
+  /// Assume ownership of raw pointer
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    rosidl_dynamic_typesupport_dynamic_type_builder_t * dynamic_type_builder);
+
+  /// Copy shared pointer
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t> dynamic_type_builder);
+
+  /// Copy constructor
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder(const DynamicMessageTypeBuilder & other);
+
+  /// Move constructor
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder(DynamicMessageTypeBuilder && other) noexcept;
+
+  /// Copy assignment
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder & operator=(const DynamicMessageTypeBuilder & other);
+
+  /// Move assignment
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder & operator=(DynamicMessageTypeBuilder && other) noexcept;
+
+  /// From description
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    const rosidl_runtime_c__type_description__TypeDescription & description);
+
+  RCLCPP_PUBLIC
+  virtual ~DynamicMessageTypeBuilder();
+
+  /// Swaps the serialization support if serialization_support is populated
+  RCLCPP_PUBLIC
+  void
+  init_from_description(
+    const rosidl_runtime_c__type_description__TypeDescription & description,
+    DynamicSerializationSupport::SharedPtr serialization_support = nullptr);
+
+
+  // GETTERS =======================================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_library_identifier() const;
+
+  RCLCPP_PUBLIC
+  const std::string
+  get_name() const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_dynamic_type_builder_t *
+  get_rosidl_dynamic_type_builder();
+
+  RCLCPP_PUBLIC
+  const rosidl_dynamic_typesupport_dynamic_type_builder_t *
+  get_rosidl_dynamic_type_builder() const;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t>
+  get_shared_rosidl_dynamic_type_builder();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<const rosidl_dynamic_typesupport_dynamic_type_builder_t>
+  get_shared_rosidl_dynamic_type_builder() const;
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support();
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::ConstSharedPtr
+  get_shared_dynamic_serialization_support() const;
+
+
+  // METHODS =======================================================================================
+  RCLCPP_PUBLIC
+  void
+  set_name(const std::string & name);
+
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder
+  clone() const;
+
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder::SharedPtr
+  clone_shared() const;
+
+  RCLCPP_PUBLIC
+  void
+  clear();
+
+  RCLCPP_PUBLIC
+  DynamicMessage
+  build_dynamic_message();
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  build_dynamic_message_shared();
+
+  RCLCPP_PUBLIC
+  DynamicMessageType
+  build_dynamic_message_type();
+
+  RCLCPP_PUBLIC
+  DynamicMessageType::SharedPtr
+  build_dynamic_message_type_shared();
+
+
+  // ADD MEMBERS TEMPLATES =========================================================================
+  /**
+   * Since we're in a ROS layer, these should support all ROS interface C++ types as found in:
+   * https://docs.ros.org/en/rolling/Concepts/About-ROS-Interfaces.html
+   *
+   * Explicitly:
+   * - Basic types:        bool, byte, char
+   * - Float types:        float, double
+   * - Int types:          int8_t, int16_t, int32_t, int64_t
+   * - Unsigned int types: uint8_t, uint16_t, uint32_t, uint64_t
+   * - String types:       std::string, std::u16string
+   */
+
+  template<typename MemberT>
+  void
+  add_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    const std::string & default_value = "");
+
+  template<typename MemberT>
+  void
+  add_array_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t array_length,
+    const std::string & default_value = "");
+
+  template<typename MemberT>
+  void
+  add_unbounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    const std::string & default_value = "");
+
+  template<typename MemberT>
+  void
+  add_bounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t sequence_bound,
+    const std::string & default_value = "");
+
+
+  // ADD FIXED STRING MEMBERS ======================================================================
+  RCLCPP_PUBLIC
+  void
+  add_fixed_string_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_length,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_wstring_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_length,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_string_array_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t string_length, size_t array_length, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_wstring_array_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t wstring_length, size_t array_length, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_string_unbounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_length,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_wstring_unbounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_length,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_string_bounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t string_length, size_t sequence_bound, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_fixed_wstring_bounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t wstring_length, size_t sequence_bound, const std::string & default_value = "");
+
+
+  // ADD BOUNDED STRING MEMBERS ====================================================================
+  RCLCPP_PUBLIC
+  void
+  add_bounded_string_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_bound,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_wstring_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_bound,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_string_array_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t string_bound, size_t array_length, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_wstring_array_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t wstring_bound, size_t array_length, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_string_unbounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_bound,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_wstring_unbounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_bound,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_string_bounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t string_bound, size_t sequence_bound, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_bounded_wstring_bounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    size_t wstring_bound, size_t sequence_bound, const std::string & default_value = "");
+
+
+  // ADD NESTED MEMBERS ============================================================================
+  RCLCPP_PUBLIC
+  void
+  add_complex_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageType & nested_type, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_array_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageType & nested_type, size_t array_length, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_unbounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageType & nested_type, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_bounded_sequence_member(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageType & nested_type, size_t sequence_bound,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_member_builder(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageTypeBuilder & nested_type_builder, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_array_member_builder(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageTypeBuilder & nested_type_builder, size_t array_length,
+    const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_unbounded_sequence_member_builder(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageTypeBuilder & nested_type_builder, const std::string & default_value = "");
+
+  RCLCPP_PUBLIC
+  void
+  add_complex_bounded_sequence_member_builder(
+    rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+    DynamicMessageTypeBuilder & nested_type_builder, size_t sequence_bound,
+    const std::string & default_value = "");
+
+protected:
+  // NOTE(methylDragon):
+  // This is just here to extend the lifetime of the serialization support
+  // It isn't actually used by the builder since the builder should compose its own support
+  //
+  // ... Though ideally it should be the exact same support as the one stored in the
+  // `DynamicSerializationSupport`
+  DynamicSerializationSupport::SharedPtr serialization_support_;
+
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t> rosidl_dynamic_type_builder_;
+
+private:
+  RCLCPP_PUBLIC
+  DynamicMessageTypeBuilder();
+
+  RCLCPP_PUBLIC
+  void
+  init_from_serialization_support_(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    const std::string & name);
+
+  RCLCPP_PUBLIC
+  bool
+  match_serialization_support_(
+    const DynamicSerializationSupport & serialization_support,
+    const rosidl_dynamic_typesupport_dynamic_type_builder_t & dynamic_type_builder);
+};
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_BUILDER_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/dynamic_message_type_support.hpp

@@ -0,0 +1,205 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_SUPPORT_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_SUPPORT_HPP_
+
+#include <rosidl_dynamic_typesupport/dynamic_message_type_support_struct.h>
+#include <rosidl_dynamic_typesupport/types.h>
+#include <rosidl_runtime_c/message_type_support_struct.h>
+#include <rosidl_runtime_c/type_description/type_description__struct.h>
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+/// Utility wrapper class for `rosidl_message_type_support_t *` containing managed
+/// instances of the typesupport handle impl.
+/**
+ *
+ * NOTE: This class is the recommended way to obtain the dynamic message type
+ *       support struct, instead of `rcl_dynamic_message_type_support_handle_create()`,
+ *       because this class will manage the lifetimes for you.
+ *
+ *       Do NOT call rcl_dynamic_message_type_support_handle_destroy!!
+ *
+ * This class:
+ * - Manages the lifetime of the raw pointer.
+ * - Exposes getter methods to get the raw pointer and shared pointers
+ * - Stores shared pointers to wrapper classes that expose the underlying
+ *   serialization support API
+ *
+ * Ownership:
+ * - This class, similarly to the `rosidl_dynamic_typesupport_serialization_support_t`, must outlive
+ *   all downstream usages of the serialization support.
+ */
+class DynamicMessageTypeSupport : public std::enable_shared_from_this<DynamicMessageTypeSupport>
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(DynamicMessageTypeSupport)
+
+  // CONSTRUCTION ==================================================================================
+  /// From description
+  /// Does NOT take ownership of the description (copies instead.)
+  /// Constructs type support top-down (calling `rcl_dynamic_message_type_support_handle_create()`)
+  RCLCPP_PUBLIC
+  DynamicMessageTypeSupport(
+    const rosidl_runtime_c__type_description__TypeDescription & description,
+    const std::string & serialization_library_name = "");
+
+  /// From description, for provided serialization support
+  /// Does NOT take ownership of the description (copies instead.)
+  /// Constructs type support top-down (calling
+  /// `rosidl_dynamic_message_type_support_handle_create()`)
+  RCLCPP_PUBLIC
+  DynamicMessageTypeSupport(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    const rosidl_runtime_c__type_description__TypeDescription & description);
+
+  /// Assume ownership of managed types
+  /// Does NOT take ownership of the description (copies instead.)
+  ///
+  /// The serialization support used to construct all managed SharedPtrs must match.
+  /// The structure of the provided `description` must match the `dynamic_message_type`
+  /// The structure of the provided `dynamic_message_type` must match the `dynamic_message
+  ///
+  /// In this case, the user would have constructed the type support bototm-up (by creating the
+  /// respective dynamic members.)
+  RCLCPP_PUBLIC
+  DynamicMessageTypeSupport(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    DynamicMessageType::SharedPtr dynamic_message_type,
+    DynamicMessage::SharedPtr dynamic_message,
+    const rosidl_runtime_c__type_description__TypeDescription & description);
+
+  RCLCPP_PUBLIC
+  virtual ~DynamicMessageTypeSupport();
+
+
+  // GETTERS =======================================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_library_identifier() const;
+
+  RCLCPP_PUBLIC
+  rosidl_message_type_support_t *
+  get_rosidl_message_type_support();
+
+  RCLCPP_PUBLIC
+  const rosidl_message_type_support_t *
+  get_rosidl_message_type_support() const;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rosidl_message_type_support_t>
+  get_shared_rosidl_message_type_support();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<const rosidl_message_type_support_t>
+  get_shared_rosidl_message_type_support() const;
+
+  RCLCPP_PUBLIC
+  rosidl_runtime_c__type_description__TypeDescription *
+  get_rosidl_runtime_c_type_description();
+
+  RCLCPP_PUBLIC
+  const rosidl_runtime_c__type_description__TypeDescription *
+  get_rosidl_runtime_c_type_description() const;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rosidl_runtime_c__type_description__TypeDescription>
+  get_shared_rosidl_runtime_c_type_description();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<const rosidl_runtime_c__type_description__TypeDescription>
+  get_shared_rosidl_runtime_c_type_description() const;
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support();
+
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport::ConstSharedPtr
+  get_shared_dynamic_serialization_support() const;
+
+  RCLCPP_PUBLIC
+  DynamicMessageType::SharedPtr
+  get_shared_dynamic_message_type();
+
+  RCLCPP_PUBLIC
+  DynamicMessageType::ConstSharedPtr
+  get_shared_dynamic_message_type() const;
+
+  RCLCPP_PUBLIC
+  DynamicMessage::SharedPtr
+  get_shared_dynamic_message();
+
+  RCLCPP_PUBLIC
+  DynamicMessage::ConstSharedPtr
+  get_shared_dynamic_message() const;
+
+protected:
+  RCLCPP_DISABLE_COPY(DynamicMessageTypeSupport)
+
+  DynamicSerializationSupport::SharedPtr serialization_support_;
+  DynamicMessageType::SharedPtr dynamic_message_type_;
+  DynamicMessage::SharedPtr dynamic_message_;
+  std::shared_ptr<rosidl_runtime_c__type_description__TypeDescription> description_;
+
+  std::shared_ptr<rosidl_message_type_support_t> rosidl_message_type_support_;
+
+private:
+  RCLCPP_PUBLIC
+  DynamicMessageTypeSupport();
+
+  RCLCPP_PUBLIC
+  void
+  manage_description_(rosidl_runtime_c__type_description__TypeDescription * description);
+
+  RCLCPP_PUBLIC
+  void
+  init_dynamic_message_type_(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    const rosidl_runtime_c__type_description__TypeDescription * description);
+
+  RCLCPP_PUBLIC
+  void
+  init_dynamic_message_(DynamicMessageType::SharedPtr dynamic_type);
+
+  // By aggregation
+  RCLCPP_PUBLIC
+  void
+  init_rosidl_message_type_support_(
+    DynamicSerializationSupport::SharedPtr serialization_support,
+    DynamicMessageType::SharedPtr dynamic_message_type,
+    DynamicMessage::SharedPtr dynamic_message,
+    rosidl_runtime_c__type_description__TypeDescription * description);
+};
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_MESSAGE_TYPE_SUPPORT_HPP_

rclcpp/include/rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp

@@ -0,0 +1,109 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_SERIALIZATION_SUPPORT_HPP_
+#define RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_SERIALIZATION_SUPPORT_HPP_
+
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+
+namespace rclcpp
+{
+namespace dynamic_typesupport
+{
+
+/// Utility wrapper class for rosidl_dynamic_typesupport_serialization_support_t *
+/**
+ * This class:
+ * - Manages the lifetime of the raw pointer.
+ * - Exposes getter methods to get the raw pointer and shared pointers
+ * - Exposes the underlying serialization support API
+ *
+ * Ownership:
+ * - This class, similarly to the rosidl_dynamic_typesupport_serialization_support_t, must outlive
+ *   all downstream usages of the serialization support.
+ */
+class DynamicSerializationSupport : public std::enable_shared_from_this<DynamicSerializationSupport>
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(DynamicSerializationSupport)
+
+  // CONSTRUCTION ==================================================================================
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport();
+
+  /// Get the rmw middleware implementation specific serialization support (configured by name)
+  RCLCPP_PUBLIC
+  explicit DynamicSerializationSupport(const std::string & serialization_library_name);
+
+  /// Assume ownership of raw pointer
+  RCLCPP_PUBLIC
+  explicit DynamicSerializationSupport(
+    rosidl_dynamic_typesupport_serialization_support_t * rosidl_serialization_support);
+
+  /// Copy shared pointer
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport(
+    std::shared_ptr<rosidl_dynamic_typesupport_serialization_support_t> serialization_support);
+
+  /// Move constructor
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport(DynamicSerializationSupport && other) noexcept;
+
+  /// Move assignment
+  RCLCPP_PUBLIC
+  DynamicSerializationSupport & operator=(DynamicSerializationSupport && other) noexcept;
+
+  RCLCPP_PUBLIC
+  virtual ~DynamicSerializationSupport();
+
+
+  // GETTERS =======================================================================================
+  RCLCPP_PUBLIC
+  const std::string
+  get_library_identifier() const;
+
+  RCLCPP_PUBLIC
+  rosidl_dynamic_typesupport_serialization_support_t *
+  get_rosidl_serialization_support();
+
+  RCLCPP_PUBLIC
+  const rosidl_dynamic_typesupport_serialization_support_t *
+  get_rosidl_serialization_support() const;
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<rosidl_dynamic_typesupport_serialization_support_t>
+  get_shared_rosidl_serialization_support();
+
+  RCLCPP_PUBLIC
+  std::shared_ptr<const rosidl_dynamic_typesupport_serialization_support_t>
+  get_shared_rosidl_serialization_support() const;
+
+protected:
+  RCLCPP_DISABLE_COPY(DynamicSerializationSupport)
+
+  std::shared_ptr<rosidl_dynamic_typesupport_serialization_support_t> rosidl_serialization_support_;
+};
+
+
+}  // namespace dynamic_typesupport
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DYNAMIC_TYPESUPPORT__DYNAMIC_SERIALIZATION_SUPPORT_HPP_

rclcpp/include/rclcpp/generic_subscription.hpp

@@ -84,7 +84,7 @@ public:
       options.to_rcl_subscription_options(qos),
       options.event_callbacks,
       options.use_default_callbacks,
-      true),
+      SubscriptionType::SERIALIZED_MESSAGE),
     callback_(callback),
     ts_lib_(ts_lib)
   {}
@@ -123,6 +123,32 @@ public:
   RCLCPP_PUBLIC
   void return_serialized_message(std::shared_ptr<rclcpp::SerializedMessage> & message) override;
 
+
+  // DYNAMIC TYPE ==================================================================================
+  // TODO(methylDragon): Reorder later
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr get_shared_dynamic_message_type()
+  override;
+
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr get_shared_dynamic_message() override;
+
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support() override;
+
+  RCLCPP_PUBLIC
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr create_dynamic_message() override;
+
+  RCLCPP_PUBLIC
+  void return_dynamic_message(
+    rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message) override;
+
+  RCLCPP_PUBLIC
+  void handle_dynamic_message(
+    const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
+    const rclcpp::MessageInfo & message_info) override;
+
 private:
   RCLCPP_DISABLE_COPY(GenericSubscription)
 

rclcpp/include/rclcpp/rclcpp.hpp

@@ -117,6 +117,21 @@
  * - Allocator related items:
  *   - rclcpp/allocator/allocator_common.hpp
  *   - rclcpp/allocator/allocator_deleter.hpp
+ * - Dynamic typesupport wrappers
+ *   - rclcpp::dynamic_typesupport::DynamicMessage
+ *   - rclcpp::dynamic_typesupport::DynamicMessageType
+ *   - rclcpp::dynamic_typesupport::DynamicMessageTypeBuilder
+ *   - rclcpp::dynamic_typesupport::DynamicSerializationSupport
+ *   - rclcpp/dynamic_typesupport/dynamic_message.hpp
+ *   - rclcpp/dynamic_typesupport/dynamic_message_type.hpp
+ *   - rclcpp/dynamic_typesupport/dynamic_message_type_builder.hpp
+ *   - rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp
+ * - Dynamic typesupport
+ *   - rclcpp::dynamic_typesupport::DynamicMessageTypeSupport
+ *   - rclcpp/dynamic_typesupport/dynamic_message_type_support.hpp
+ * - Dynamic subscription
+ *   - rclcpp::DynamicSubscription
+ *   - rclcpp/dynamic_subscription.hpp
  * - Generic publisher
  *   - rclcpp::Node::create_generic_publisher()
  *   - rclcpp::GenericPublisher
@@ -167,4 +182,6 @@
 #include "rclcpp/waitable.hpp"
 #include "rclcpp/wait_set.hpp"
 
+#include "rclcpp/dynamic_subscription.hpp"
+
 #endif  // RCLCPP__RCLCPP_HPP_

rclcpp/include/rclcpp/subscription.hpp

@@ -144,7 +144,7 @@ public:
       // NOTE(methylDragon): Passing these args separately is necessary for event binding
       options.event_callbacks,
       options.use_default_callbacks,
-      callback.is_serialized_message_callback()),
+      callback.is_serialized_message_callback() ? SubscriptionType::SERIALIZED_MESSAGE : SubscriptionType::ROS_MESSAGE),  // NOLINT
     any_callback_(callback),
     options_(options),
     message_memory_strategy_(message_memory_strategy)
@@ -388,6 +388,57 @@ public:
     return any_callback_.use_take_shared_method();
   }
 
+  // DYNAMIC TYPE ==================================================================================
+  // TODO(methylDragon): Reorder later
+  // TODO(methylDragon): Implement later...
+  rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr
+  get_shared_dynamic_message_type() override
+  {
+    throw rclcpp::exceptions::UnimplementedError(
+            "get_shared_dynamic_message_type is not implemented for Subscription");
+  }
+
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+  get_shared_dynamic_message() override
+  {
+    throw rclcpp::exceptions::UnimplementedError(
+            "get_shared_dynamic_message is not implemented for Subscription");
+  }
+
+  rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support() override
+  {
+    throw rclcpp::exceptions::UnimplementedError(
+            "get_shared_dynamic_serialization_support is not implemented for Subscription");
+  }
+
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+  create_dynamic_message() override
+  {
+    throw rclcpp::exceptions::UnimplementedError(
+            "create_dynamic_message is not implemented for Subscription");
+  }
+
+  void
+  return_dynamic_message(
+    rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message) override
+  {
+    (void) message;
+    throw rclcpp::exceptions::UnimplementedError(
+            "return_dynamic_message is not implemented for Subscription");
+  }
+
+  void
+  handle_dynamic_message(
+    const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
+    const rclcpp::MessageInfo & message_info) override
+  {
+    (void) message;
+    (void) message_info;
+    throw rclcpp::exceptions::UnimplementedError(
+            "handle_dynamic_message is not implemented for Subscription");
+  }
+
 private:
   RCLCPP_DISABLE_COPY(Subscription)
 

rclcpp/include/rclcpp/subscription_base.hpp

@@ -31,6 +31,9 @@
 
 #include "rclcpp/any_subscription_callback.hpp"
 #include "rclcpp/detail/cpp_callback_trampoline.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
 #include "rclcpp/experimental/intra_process_manager.hpp"
 #include "rclcpp/experimental/subscription_intra_process_base.hpp"
 #include "rclcpp/macros.hpp"
@@ -60,6 +63,14 @@ namespace experimental
 class IntraProcessManager;
 }  // namespace experimental
 
+enum class SubscriptionType : uint8_t
+{
+  ROS_MESSAGE = 1,  // take message as ROS message and handle as ROS message
+  SERIALIZED_MESSAGE = 2,  // take message as serialized and handle as serialized
+  DYNAMIC_MESSAGE_DIRECT = 3,  // take message as DynamicMessage and handle as DynamicMessage
+  DYNAMIC_MESSAGE_FROM_SERIALIZED = 4  // take message as serialized and handle as DynamicMessage
+};
+
 /// Virtual base class for subscriptions. This pattern allows us to iterate over different template
 /// specializations of Subscription, among other things.
 class SubscriptionBase : public std::enable_shared_from_this<SubscriptionBase>
@@ -76,7 +87,7 @@ public:
    * \param[in] type_support_handle rosidl type support struct, for the Message type of the topic.
    * \param[in] topic_name Name of the topic to subscribe to.
    * \param[in] subscription_options Options for the subscription.
-   * \param[in] is_serialized is true if the message will be delivered still serialized
+   * \param[in] subscription_type Enum flag to change how the message will be received and delivered
    */
   RCLCPP_PUBLIC
   SubscriptionBase(
@@ -86,7 +97,7 @@ public:
     const rcl_subscription_options_t & subscription_options,
     const SubscriptionEventCallbacks & event_callbacks,
     bool use_default_callbacks,
-    bool is_serialized = false);
+    SubscriptionType subscription_type = SubscriptionType::ROS_MESSAGE);
 
   /// Destructor.
   RCLCPP_PUBLIC
@@ -227,13 +238,13 @@ public:
   const rosidl_message_type_support_t &
   get_message_type_support_handle() const;
 
-  /// Return if the subscription is serialized
+  /// Return the type of the subscription.
   /**
-   * \return `true` if the subscription is serialized, `false` otherwise
+   * \return `SubscriptionType`, which adjusts how messages are received and delivered.
    */
   RCLCPP_PUBLIC
-  bool
-  is_serialized() const;
+  SubscriptionType
+  get_subscription_type() const;
 
   /// Get matching publisher count.
   /** \return The number of publishers on this topic. */
@@ -535,6 +546,49 @@ public:
   rclcpp::ContentFilterOptions
   get_content_filter() const;
 
+  // DYNAMIC TYPE ==================================================================================
+  // TODO(methylDragon): Reorder later
+  RCLCPP_PUBLIC
+  virtual
+  rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr
+  get_shared_dynamic_message_type() = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+  get_shared_dynamic_message() = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
+  get_shared_dynamic_serialization_support() = 0;
+
+  /// Borrow a new serialized message (this clones!)
+  /** \return Shared pointer to a rclcpp::dynamic_typesupport::DynamicMessage. */
+  RCLCPP_PUBLIC
+  virtual
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+  create_dynamic_message() = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  void
+  return_dynamic_message(rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message) = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  void
+  handle_dynamic_message(
+    const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
+    const rclcpp::MessageInfo & message_info) = 0;
+
+  RCLCPP_PUBLIC
+  bool
+  take_dynamic_message(
+    rclcpp::dynamic_typesupport::DynamicMessage & message_out,
+    rclcpp::MessageInfo & message_info_out);
+  // ===============================================================================================
+
 protected:
   template<typename EventCallbackT>
   void
@@ -568,6 +622,10 @@ protected:
 
   rclcpp::node_interfaces::NodeBaseInterface * const node_base_;
 
+  // TODO(methylDragon): Remove if we don't need this
+  // rclcpp::node_interfaces::NodeGraphInterface * const node_graph_;
+  // rclcpp::node_interfaces::NodeServicesInterface * const node_services_;
+
   std::shared_ptr<rcl_node_t> node_handle_;
   std::shared_ptr<rcl_subscription_t> subscription_handle_;
   std::shared_ptr<rcl_subscription_t> intra_process_subscription_handle_;
@@ -587,7 +645,7 @@ private:
   RCLCPP_DISABLE_COPY(SubscriptionBase)
 
   rosidl_message_type_support_t type_support_;
-  bool is_serialized_;
+  SubscriptionType subscription_type_;
 
   std::atomic<bool> subscription_in_use_by_wait_set_{false};
   std::atomic<bool> intra_process_subscription_waitable_in_use_by_wait_set_{false};

rclcpp/package.xml

@@ -39,6 +39,7 @@
   <depend>rcpputils</depend>
   <depend>rcutils</depend>
   <depend>rmw</depend>
+  <depend>rosidl_dynamic_typesupport</depend>
   <depend>statistics_msgs</depend>
   <depend>tracetools</depend>
 

rclcpp/src/rclcpp/dynamic_subscription.cpp

@@ -0,0 +1,113 @@
+// Copyright 2022 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "rclcpp/dynamic_subscription.hpp"
+
+#include <memory>
+#include <string>
+
+#include "rcl/subscription.h"
+
+#include "rclcpp/exceptions.hpp"
+
+namespace rclcpp
+{
+
+std::shared_ptr<void> DynamicSubscription::create_message()
+{
+  return create_serialized_message();
+}
+
+std::shared_ptr<rclcpp::SerializedMessage> DynamicSubscription::create_serialized_message()
+{
+  return std::make_shared<rclcpp::SerializedMessage>(0);
+}
+
+void DynamicSubscription::handle_message(std::shared_ptr<void> &, const rclcpp::MessageInfo &)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "handle_message is not implemented for DynamicSubscription");
+}
+
+void DynamicSubscription::handle_serialized_message(
+  const std::shared_ptr<rclcpp::SerializedMessage> &, const rclcpp::MessageInfo &)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "handle_serialized_message is not implemented for DynamicSubscription");
+}
+
+void DynamicSubscription::handle_loaned_message(void *, const rclcpp::MessageInfo &)
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "handle_loaned_message is not implemented for DynamicSubscription");
+}
+
+void DynamicSubscription::return_message(std::shared_ptr<void> & message)
+{
+  auto typed_message = std::static_pointer_cast<rclcpp::SerializedMessage>(message);
+  return_serialized_message(typed_message);
+}
+
+void DynamicSubscription::return_serialized_message(
+  std::shared_ptr<rclcpp::SerializedMessage> & message)
+{
+  message.reset();
+}
+
+
+// DYNAMIC TYPE ====================================================================================
+// TODO(methylDragon): Re-order later
+
+// Does not clone
+rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr
+DynamicSubscription::get_shared_dynamic_message_type()
+{
+  return dynamic_message_type_;
+}
+
+// Does not clone
+rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+DynamicSubscription::get_shared_dynamic_message()
+{
+  return dynamic_message_;
+}
+
+rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
+DynamicSubscription::get_shared_dynamic_serialization_support()
+{
+  return serialization_support_;
+}
+
+rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+DynamicSubscription::create_dynamic_message()
+{
+  return dynamic_message_->init_from_type_shared(*dynamic_message_type_);
+}
+
+void
+DynamicSubscription::return_dynamic_message(
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message)
+{
+  message.reset();
+}
+
+void DynamicSubscription::handle_dynamic_message(
+  const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
+  const rclcpp::MessageInfo & message_info)
+{
+  (void) message_info;
+  callback_(message, ts_->get_shared_rosidl_runtime_c_type_description());
+}
+
+}  // namespace rclcpp

rclcpp/src/rclcpp/dynamic_typesupport/dynamic_message.cpp

@@ -0,0 +1,838 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <rosidl_dynamic_typesupport/api/dynamic_type.h>
+#include <rosidl_dynamic_typesupport/api/dynamic_data.h>
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rcl/types.h"
+#include "rcutils/logging_macros.h"
+
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type_builder.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/exceptions.hpp"
+
+
+using rclcpp::dynamic_typesupport::DynamicMessage;
+using rclcpp::dynamic_typesupport::DynamicMessageType;
+using rclcpp::dynamic_typesupport::DynamicMessageTypeBuilder;
+using rclcpp::dynamic_typesupport::DynamicSerializationSupport;
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_IMPL_HPP_
+// Template specialization implementations
+#include "rclcpp/dynamic_typesupport/detail/dynamic_message_impl.hpp"
+#endif
+
+
+// CONSTRUCTION ==================================================================================
+DynamicMessage::DynamicMessage(const DynamicMessageTypeBuilder::SharedPtr dynamic_type_builder)
+: serialization_support_(dynamic_type_builder->get_shared_dynamic_serialization_support()),
+  rosidl_dynamic_data_(nullptr),
+  is_loaned_(false),
+  parent_data_(nullptr)
+{
+  if (!serialization_support_) {
+    throw std::runtime_error("dynamic type could not bind serialization support!");
+  }
+
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder =
+    dynamic_type_builder->get_rosidl_dynamic_type_builder();
+  if (!rosidl_dynamic_type_builder) {
+    throw std::runtime_error("dynamic type builder cannot be nullptr!");
+  }
+
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_create_from_dynamic_type_builder(
+    rosidl_dynamic_type_builder, &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error("could not create new dynamic data object from dynamic type builder");
+  }
+
+  rosidl_dynamic_data_.reset(
+    rosidl_dynamic_data,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data)->void {
+      rosidl_dynamic_typesupport_dynamic_data_destroy(rosidl_dynamic_data);
+    });
+}
+
+
+DynamicMessage::DynamicMessage(const DynamicMessageType::SharedPtr dynamic_type)
+: serialization_support_(dynamic_type->get_shared_dynamic_serialization_support()),
+  rosidl_dynamic_data_(nullptr),
+  is_loaned_(false),
+  parent_data_(nullptr)
+{
+  if (!serialization_support_) {
+    throw std::runtime_error("dynamic type could not bind serialization support!");
+  }
+
+  rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type =
+    dynamic_type->get_rosidl_dynamic_type();
+  if (!rosidl_dynamic_type) {
+    throw std::runtime_error("dynamic type cannot be nullptr!");
+  }
+
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_create_from_dynamic_type(
+    rosidl_dynamic_type, &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error(
+            std::string("could not create new dynamic data object from dynamic type") +
+            rcl_get_error_string().str);
+  }
+
+  rosidl_dynamic_data_.reset(
+    rosidl_dynamic_data,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data)->void {
+      rosidl_dynamic_typesupport_dynamic_data_destroy(rosidl_dynamic_data);
+    });
+}
+
+
+DynamicMessage::DynamicMessage(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data)
+: serialization_support_(serialization_support),
+  rosidl_dynamic_data_(nullptr),
+  is_loaned_(false),
+  parent_data_(nullptr)
+{
+  if (!rosidl_dynamic_data) {
+    throw std::runtime_error("rosidl dynamic data cannot be nullptr!");
+  }
+  if (serialization_support) {
+    if (!match_serialization_support_(*serialization_support, *rosidl_dynamic_data)) {
+      throw std::runtime_error(
+              "serialization support library identifier does not match dynamic data's!");
+    }
+  }
+
+  rosidl_dynamic_data_.reset(
+    rosidl_dynamic_data,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data)->void {
+      rosidl_dynamic_typesupport_dynamic_data_destroy(rosidl_dynamic_data);
+    });
+}
+
+
+DynamicMessage::DynamicMessage(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t> rosidl_dynamic_data)
+: serialization_support_(serialization_support),
+  rosidl_dynamic_data_(rosidl_dynamic_data),
+  is_loaned_(false),
+  parent_data_(nullptr)
+{
+  if (!rosidl_dynamic_data) {
+    throw std::runtime_error("rosidl dynamic data cannot be nullptr!");
+  }
+  if (serialization_support) {
+    if (!match_serialization_support_(*serialization_support, *rosidl_dynamic_data)) {
+      throw std::runtime_error(
+              "serialization support library identifier does not match dynamic data's!");
+    }
+  }
+}
+
+
+DynamicMessage::DynamicMessage(
+  DynamicMessage::SharedPtr parent_data,
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_loaned_data)
+: serialization_support_(parent_data->get_shared_dynamic_serialization_support()),
+  rosidl_dynamic_data_(nullptr),
+  is_loaned_(true),
+  parent_data_(nullptr)
+{
+  if (!parent_data) {
+    throw std::runtime_error("parent dynamic data cannot be nullptr!");
+  }
+  if (!rosidl_loaned_data) {
+    throw std::runtime_error("loaned rosidl dynamic data cannot be nullptr!");
+  }
+
+  if (serialization_support_) {
+    if (!match_serialization_support_(*serialization_support_, *rosidl_loaned_data)) {
+      throw std::runtime_error(
+              "serialization support library identifier does not match loaned dynamic data's!");
+    }
+  }
+
+  rosidl_dynamic_data_.reset(
+    rosidl_loaned_data,
+    // Custom no-op deleter
+    [](rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data)->void {
+      // Data fini and destruction is deferred to return_loaned_value()
+      (void) rosidl_dynamic_data;
+    });
+  parent_data_ = parent_data;
+}
+
+
+DynamicMessage::DynamicMessage(const DynamicMessage & other)
+: enable_shared_from_this(),
+  serialization_support_(nullptr),
+  rosidl_dynamic_data_(nullptr),
+  is_loaned_(false),
+  parent_data_(nullptr)
+{
+  DynamicMessage out = other.clone();
+  // We don't copy is_loaned_ or parent_data_ because it's a fresh copy now
+  std::swap(serialization_support_, out.serialization_support_);
+  std::swap(rosidl_dynamic_data_, out.rosidl_dynamic_data_);
+}
+
+
+DynamicMessage::DynamicMessage(DynamicMessage && other) noexcept
+: serialization_support_(std::exchange(other.serialization_support_, nullptr)),
+  rosidl_dynamic_data_(std::exchange(other.rosidl_dynamic_data_, nullptr)),
+  is_loaned_(other.is_loaned_),
+  parent_data_(std::exchange(other.parent_data_, nullptr))
+{}
+
+
+DynamicMessage &
+DynamicMessage::operator=(const DynamicMessage & other)
+{
+  return *this = DynamicMessage(other);
+}
+
+
+DynamicMessage &
+DynamicMessage::operator=(DynamicMessage && other) noexcept
+{
+  std::swap(serialization_support_, other.serialization_support_);
+  std::swap(rosidl_dynamic_data_, other.rosidl_dynamic_data_);
+  is_loaned_ = other.is_loaned_;
+  std::swap(parent_data_, other.parent_data_);
+  return *this;
+}
+
+
+DynamicMessage::~DynamicMessage()
+{
+  if (is_loaned_) {
+    if (!parent_data_) {
+      RCUTILS_LOG_ERROR("dynamic data is loaned, but parent is missing!!");
+    } else {
+      rosidl_dynamic_typesupport_dynamic_data_return_loaned_value(
+        parent_data_->get_rosidl_dynamic_data(), get_rosidl_dynamic_data());
+    }
+  }
+}
+
+
+bool
+DynamicMessage::match_serialization_support_(
+  const DynamicSerializationSupport & serialization_support,
+  const rosidl_dynamic_typesupport_dynamic_data_t & rosidl_dynamic_type_data)
+{
+  bool out = true;
+
+  if (serialization_support.get_library_identifier() != std::string(
+      rosidl_dynamic_type_data.serialization_support->library_identifier))
+  {
+    RCUTILS_LOG_ERROR("serialization support library identifier does not match dynamic data's");
+    out = false;
+  }
+
+  // TODO(methylDragon): Can I do this?? Is it portable?
+  if (serialization_support.get_rosidl_serialization_support() !=
+    rosidl_dynamic_type_data.serialization_support)
+  {
+    RCUTILS_LOG_ERROR("serialization support pointer does not match dynamic data's");
+    out = false;
+  }
+
+  return out;
+}
+
+
+// GETTERS =======================================================================================
+const std::string
+DynamicMessage::get_library_identifier() const
+{
+  return std::string(rosidl_dynamic_data_->serialization_support->library_identifier);
+}
+
+
+const std::string
+DynamicMessage::get_name() const
+{
+  size_t buf_length;
+  const char * buf;
+  if (
+    rosidl_dynamic_typesupport_dynamic_data_get_name(
+      get_rosidl_dynamic_data(), &buf,
+      &buf_length) !=
+    RCUTILS_RET_OK)
+  {
+    throw std::runtime_error(
+            std::string("could not get name for dynamic data") + rcl_get_error_string().str);
+  }
+  return std::string(buf, buf_length);
+}
+
+
+rosidl_dynamic_typesupport_dynamic_data_t *
+DynamicMessage::get_rosidl_dynamic_data()
+{
+  return rosidl_dynamic_data_.get();
+}
+
+
+const rosidl_dynamic_typesupport_dynamic_data_t *
+DynamicMessage::get_rosidl_dynamic_data() const
+{
+  return rosidl_dynamic_data_.get();
+}
+
+
+std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t>
+DynamicMessage::get_shared_rosidl_dynamic_data()
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t>(
+    shared_from_this(), rosidl_dynamic_data_.get());
+}
+
+
+std::shared_ptr<const rosidl_dynamic_typesupport_dynamic_data_t>
+DynamicMessage::get_shared_rosidl_dynamic_data() const
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_dynamic_data_t>(
+    shared_from_this(), rosidl_dynamic_data_.get());
+}
+
+
+DynamicSerializationSupport::SharedPtr
+DynamicMessage::get_shared_dynamic_serialization_support()
+{
+  return serialization_support_;
+}
+
+
+DynamicSerializationSupport::ConstSharedPtr
+DynamicMessage::get_shared_dynamic_serialization_support() const
+{
+  return serialization_support_;
+}
+
+
+size_t
+DynamicMessage::get_item_count() const
+{
+  size_t item_count;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_get_item_count(
+    get_rosidl_dynamic_data(), &item_count);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error("could not get item count of dynamic data");
+  }
+  return item_count;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::get_member_id(size_t index) const
+{
+  rosidl_dynamic_typesupport_member_id_t member_id;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_get_member_id_at_index(
+    get_rosidl_dynamic_data(), index, &member_id);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error("could not member id of dynamic data element by index");
+  }
+  return member_id;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::get_member_id(const std::string & name) const
+{
+  rosidl_dynamic_typesupport_member_id_t member_id;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_get_member_id_by_name(
+    get_rosidl_dynamic_data(), name.c_str(), name.size(), &member_id);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error("could not member id of dynamic data element by name");
+  }
+  return member_id;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::get_array_index(size_t index) const
+{
+  rosidl_dynamic_typesupport_member_id_t array_index;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_get_array_index(
+    get_rosidl_dynamic_data(), index, &array_index);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error("could not array index of dynamic data element by index");
+  }
+  return array_index;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::get_array_index(const std::string & name) const
+{
+  return get_array_index(get_member_id(name));
+}
+
+
+// METHODS =======================================================================================
+DynamicMessage
+DynamicMessage::clone() const
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_clone(
+    get_rosidl_dynamic_data(), &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error(
+            std::string("could not clone dynamic data: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessage(serialization_support_, rosidl_dynamic_data);
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessage::clone_shared() const
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_clone(
+    get_rosidl_dynamic_data(), &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error(
+            std::string("could not clone dynamic data: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessage::make_shared(serialization_support_, rosidl_dynamic_data);
+}
+
+
+DynamicMessage
+DynamicMessage::init_from_type(DynamicMessageType & type) const
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_create_from_dynamic_type(
+    type.get_rosidl_dynamic_type(), &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error("could not create new dynamic data object from dynamic type");
+  }
+  return DynamicMessage(serialization_support_, rosidl_dynamic_data);
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessage::init_from_type_shared(DynamicMessageType & type) const
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_create_from_dynamic_type(
+    type.get_rosidl_dynamic_type(), &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error("could not create new dynamic data object from dynamic type");
+  }
+  return DynamicMessage::make_shared(serialization_support_, rosidl_dynamic_data);
+}
+
+
+bool
+DynamicMessage::equals(const DynamicMessage & other) const
+{
+  if (get_library_identifier() != other.get_library_identifier()) {
+    throw std::runtime_error("library identifiers don't match");
+  }
+  bool equals;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_equals(
+    get_rosidl_dynamic_data(), other.get_rosidl_dynamic_data(), &equals);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error("could not equate dynamic messages");
+  }
+  return equals;
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessage::loan_value(rosidl_dynamic_typesupport_member_id_t id)
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * rosidl_dynamic_data = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_data_loan_value(
+    get_rosidl_dynamic_data(), id, &rosidl_dynamic_data);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_data) {
+    throw std::runtime_error(
+            std::string("could not loan dynamic data: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessage::make_shared(shared_from_this(), rosidl_dynamic_data);
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessage::loan_value(const std::string & name)
+{
+  return loan_value(get_member_id(name));
+}
+
+
+void
+DynamicMessage::clear_all_values()
+{
+  rosidl_dynamic_typesupport_dynamic_data_clear_all_values(get_rosidl_dynamic_data());
+}
+
+
+void
+DynamicMessage::clear_nonkey_values()
+{
+  rosidl_dynamic_typesupport_dynamic_data_clear_nonkey_values(get_rosidl_dynamic_data());
+}
+
+
+void
+DynamicMessage::clear_value(rosidl_dynamic_typesupport_member_id_t id)
+{
+  rosidl_dynamic_typesupport_dynamic_data_clear_value(get_rosidl_dynamic_data(), id);
+}
+
+
+void
+DynamicMessage::clear_value(const std::string & name)
+{
+  clear_value(get_member_id(name));
+}
+
+
+void
+DynamicMessage::clear_sequence()
+{
+  rosidl_dynamic_typesupport_dynamic_data_clear_sequence_data(get_rosidl_dynamic_data());
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_sequence_data()
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_sequence_data(get_rosidl_dynamic_data(), &out);
+  return out;
+}
+
+
+void
+DynamicMessage::remove_sequence_data(rosidl_dynamic_typesupport_member_id_t index)
+{
+  rosidl_dynamic_typesupport_dynamic_data_remove_sequence_data(
+    get_rosidl_dynamic_data(), index);
+}
+
+
+bool
+DynamicMessage::serialize(rcl_serialized_message_t * buffer)
+{
+  bool success;
+  rcutils_ret_t ret =
+    rosidl_dynamic_typesupport_dynamic_data_serialize(get_rosidl_dynamic_data(), buffer, &success);
+  if (ret != RCUTILS_RET_OK || !success) {
+    throw std::runtime_error(
+            std::string("could serialize loan dynamic data: ") + rcl_get_error_string().str);
+  }
+  return success;
+}
+
+
+bool
+DynamicMessage::deserialize(rcl_serialized_message_t * buffer)
+{
+  bool success;
+  rcutils_ret_t ret =
+    rosidl_dynamic_typesupport_dynamic_data_deserialize(
+    get_rosidl_dynamic_data(), buffer,
+    &success);
+  if (ret != RCUTILS_RET_OK || !success) {
+    throw std::runtime_error(
+            std::string("could deserialize loan dynamic data: ") + rcl_get_error_string().str);
+  }
+  return success;
+}
+
+
+// MEMBER ACCESS ===================================================================================
+// Defined in "detail/dynamic_message_impl.hpp"
+
+
+// FIXED STRING MEMBER ACCESS ======================================================================
+const std::string
+DynamicMessage::get_fixed_string_value(
+  rosidl_dynamic_typesupport_member_id_t id, size_t string_length)
+{
+  size_t buf_length;
+  char * buf = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_fixed_string_value(
+    get_rosidl_dynamic_data(), id, &buf, &buf_length, string_length);
+  auto out = std::string(buf, buf_length);
+  delete buf;
+  return out;
+}
+
+
+const std::string
+DynamicMessage::get_fixed_string_value(const std::string & name, size_t string_length)
+{
+  return get_fixed_string_value(get_member_id(name), string_length);
+}
+
+
+const std::u16string
+DynamicMessage::get_fixed_wstring_value(
+  rosidl_dynamic_typesupport_member_id_t id, size_t wstring_length)
+{
+  size_t buf_length;
+  char16_t * buf = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_fixed_wstring_value(
+    get_rosidl_dynamic_data(), id, &buf, &buf_length, wstring_length);
+  auto out = std::u16string(buf, buf_length);
+  delete buf;
+  return out;
+}
+
+
+const std::u16string
+DynamicMessage::get_fixed_wstring_value(const std::string & name, size_t wstring_length)
+{
+  return get_fixed_wstring_value(get_member_id(name), wstring_length);
+}
+
+
+void
+DynamicMessage::set_fixed_string_value(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string value, size_t string_length)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_fixed_string_value(
+    get_rosidl_dynamic_data(), id, value.c_str(), value.size(), string_length);
+}
+
+
+void
+DynamicMessage::set_fixed_string_value(
+  const std::string & name, const std::string value, size_t string_length)
+{
+  set_fixed_string_value(get_member_id(name), value, string_length);
+}
+
+
+void
+DynamicMessage::set_fixed_wstring_value(
+  rosidl_dynamic_typesupport_member_id_t id, const std::u16string value, size_t wstring_length)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_fixed_wstring_value(
+    get_rosidl_dynamic_data(), id, value.c_str(), value.size(), wstring_length);
+}
+
+
+void
+DynamicMessage::set_fixed_wstring_value(
+  const std::string & name, const std::u16string value, size_t wstring_length)
+{
+  set_fixed_wstring_value(get_member_id(name), value, wstring_length);
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_fixed_string_value(const std::string value, size_t string_length)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_fixed_string_value(
+    get_rosidl_dynamic_data(), value.c_str(), value.size(), string_length, &out);
+  return out;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_fixed_wstring_value(const std::u16string value, size_t wstring_length)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_fixed_wstring_value(
+    get_rosidl_dynamic_data(), value.c_str(), value.size(), wstring_length, &out);
+  return out;
+}
+
+
+// BOUNDED STRING MEMBER ACCESS ====================================================================
+const std::string
+DynamicMessage::get_bounded_string_value(
+  rosidl_dynamic_typesupport_member_id_t id, size_t string_bound)
+{
+  size_t buf_length;
+  char * buf = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_bounded_string_value(
+    get_rosidl_dynamic_data(), id, &buf, &buf_length, string_bound);
+  auto out = std::string(buf, buf_length);
+  delete buf;
+  return out;
+}
+
+
+const std::string
+DynamicMessage::get_bounded_string_value(const std::string & name, size_t string_bound)
+{
+  return get_bounded_string_value(get_member_id(name), string_bound);
+}
+
+
+const std::u16string
+DynamicMessage::get_bounded_wstring_value(
+  rosidl_dynamic_typesupport_member_id_t id, size_t wstring_bound)
+{
+  size_t buf_length;
+  char16_t * buf = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_bounded_wstring_value(
+    get_rosidl_dynamic_data(), id, &buf, &buf_length, wstring_bound);
+  auto out = std::u16string(buf, buf_length);
+  delete buf;
+  return out;
+}
+
+
+const std::u16string
+DynamicMessage::get_bounded_wstring_value(const std::string & name, size_t wstring_bound)
+{
+  return get_bounded_wstring_value(get_member_id(name), wstring_bound);
+}
+
+
+void
+DynamicMessage::set_bounded_string_value(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string value, size_t string_bound)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_bounded_string_value(
+    get_rosidl_dynamic_data(), id, value.c_str(), value.size(), string_bound);
+}
+
+
+void
+DynamicMessage::set_bounded_string_value(
+  const std::string & name, const std::string value, size_t string_bound)
+{
+  set_bounded_string_value(get_member_id(name), value, string_bound);
+}
+
+
+void
+DynamicMessage::set_bounded_wstring_value(
+  rosidl_dynamic_typesupport_member_id_t id, const std::u16string value, size_t wstring_bound)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_bounded_wstring_value(
+    get_rosidl_dynamic_data(), id, value.c_str(), value.size(), wstring_bound);
+}
+
+
+void
+DynamicMessage::set_bounded_wstring_value(
+  const std::string & name, const std::u16string value, size_t wstring_bound)
+{
+  set_bounded_wstring_value(get_member_id(name), value, wstring_bound);
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_bounded_string_value(const std::string value, size_t string_bound)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_bounded_string_value(
+    get_rosidl_dynamic_data(), value.c_str(), value.size(), string_bound, &out);
+  return out;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_bounded_wstring_value(const std::u16string value, size_t wstring_bound)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_bounded_wstring_value(
+    get_rosidl_dynamic_data(), value.c_str(), value.size(), wstring_bound, &out);
+  return out;
+}
+
+
+// NESTED MEMBER ACCESS ============================================================================
+DynamicMessage
+DynamicMessage::get_complex_value(rosidl_dynamic_typesupport_member_id_t id)
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * out_ptr = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_complex_value(
+    get_rosidl_dynamic_data(), id, &out_ptr);
+  return DynamicMessage(get_shared_dynamic_serialization_support(), out_ptr);
+}
+
+
+DynamicMessage
+DynamicMessage::get_complex_value(const std::string & name)
+{
+  return get_complex_value(get_member_id(name));
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessage::get_complex_value_shared(rosidl_dynamic_typesupport_member_id_t id)
+{
+  rosidl_dynamic_typesupport_dynamic_data_t * out_ptr = nullptr;
+  rosidl_dynamic_typesupport_dynamic_data_get_complex_value(
+    get_rosidl_dynamic_data(), id, &out_ptr);
+  return DynamicMessage::make_shared(get_shared_dynamic_serialization_support(), out_ptr);
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessage::get_complex_value_shared(const std::string & name)
+{
+  return get_complex_value_shared(get_member_id(name));
+}
+
+
+void
+DynamicMessage::set_complex_value(
+  rosidl_dynamic_typesupport_member_id_t id, DynamicMessage & value)
+{
+  rosidl_dynamic_typesupport_dynamic_data_set_complex_value(
+    get_rosidl_dynamic_data(), id, value.get_rosidl_dynamic_data());
+}
+
+
+void
+DynamicMessage::set_complex_value(const std::string & name, DynamicMessage & value)
+{
+  set_complex_value(get_member_id(name), value);
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_complex_value_copy(const DynamicMessage & value)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_complex_value_copy(
+    get_rosidl_dynamic_data(), value.get_rosidl_dynamic_data(), &out);
+  return out;
+}
+
+
+rosidl_dynamic_typesupport_member_id_t
+DynamicMessage::insert_complex_value(DynamicMessage & value)
+{
+  rosidl_dynamic_typesupport_member_id_t out;
+  rosidl_dynamic_typesupport_dynamic_data_insert_complex_value(
+    get_rosidl_dynamic_data(), value.get_rosidl_dynamic_data(), &out);
+  return out;
+}

rclcpp/src/rclcpp/dynamic_typesupport/dynamic_message_type.cpp

@@ -0,0 +1,338 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <rosidl_dynamic_typesupport/api/dynamic_data.h>
+#include <rosidl_dynamic_typesupport/api/dynamic_type.h>
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rcutils/logging_macros.h"
+
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type_builder.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/exceptions.hpp"
+
+
+using rclcpp::dynamic_typesupport::DynamicMessage;
+using rclcpp::dynamic_typesupport::DynamicMessageType;
+using rclcpp::dynamic_typesupport::DynamicMessageTypeBuilder;
+using rclcpp::dynamic_typesupport::DynamicSerializationSupport;
+
+
+// CONSTRUCTION ====================================================================================
+DynamicMessageType::DynamicMessageType(DynamicMessageTypeBuilder::SharedPtr dynamic_type_builder)
+: serialization_support_(dynamic_type_builder->get_shared_dynamic_serialization_support()),
+  rosidl_dynamic_type_(nullptr)
+{
+  if (!serialization_support_) {
+    throw std::runtime_error("dynamic type could not bind serialization support!");
+  }
+
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder =
+    dynamic_type_builder->get_rosidl_dynamic_type_builder();
+  if (!rosidl_dynamic_type_builder) {
+    throw std::runtime_error("dynamic type builder cannot be nullptr!");
+  }
+
+  rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_create_from_dynamic_type_builder(
+    rosidl_dynamic_type_builder, &rosidl_dynamic_type);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type) {
+    throw std::runtime_error("could not create new dynamic type object");
+  }
+
+  rosidl_dynamic_type_.reset(
+    rosidl_dynamic_type,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type)->void {
+      rosidl_dynamic_typesupport_dynamic_type_destroy(rosidl_dynamic_type);
+    });
+}
+
+
+DynamicMessageType::DynamicMessageType(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type)
+: serialization_support_(serialization_support), rosidl_dynamic_type_(nullptr)
+{
+  if (!rosidl_dynamic_type) {
+    throw std::runtime_error("rosidl dynamic type cannot be nullptr!");
+  }
+  if (serialization_support) {
+    if (!match_serialization_support_(*serialization_support, *rosidl_dynamic_type)) {
+      throw std::runtime_error(
+              "serialization support library identifier does not match dynamic type's!");
+    }
+  }
+
+  rosidl_dynamic_type_.reset(
+    rosidl_dynamic_type,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type)->void {
+      rosidl_dynamic_typesupport_dynamic_type_destroy(rosidl_dynamic_type);
+    });
+}
+
+
+DynamicMessageType::DynamicMessageType(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t> rosidl_dynamic_type)
+: serialization_support_(serialization_support), rosidl_dynamic_type_(rosidl_dynamic_type)
+{
+  if (!rosidl_dynamic_type) {
+    throw std::runtime_error("rosidl dynamic type cannot be nullptr!");
+  }
+  if (serialization_support) {
+    if (!match_serialization_support_(*serialization_support, *rosidl_dynamic_type)) {
+      throw std::runtime_error(
+              "serialization support library identifier does not match dynamic type's!");
+    }
+  }
+}
+
+
+DynamicMessageType::DynamicMessageType(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  const rosidl_runtime_c__type_description__TypeDescription & description)
+: serialization_support_(serialization_support), rosidl_dynamic_type_(nullptr)
+{
+  init_from_description(description, serialization_support);
+}
+
+
+DynamicMessageType::DynamicMessageType(const DynamicMessageType & other)
+: enable_shared_from_this(), serialization_support_(nullptr), rosidl_dynamic_type_(nullptr)
+{
+  DynamicMessageType out = other.clone();
+  std::swap(serialization_support_, out.serialization_support_);
+  std::swap(rosidl_dynamic_type_, out.rosidl_dynamic_type_);
+}
+
+
+DynamicMessageType::DynamicMessageType(DynamicMessageType && other) noexcept
+: serialization_support_(std::exchange(other.serialization_support_, nullptr)),
+  rosidl_dynamic_type_(std::exchange(other.rosidl_dynamic_type_, nullptr)) {}
+
+
+DynamicMessageType &
+DynamicMessageType::operator=(const DynamicMessageType & other)
+{
+  return *this = DynamicMessageType(other);
+}
+
+
+DynamicMessageType &
+DynamicMessageType::operator=(DynamicMessageType && other) noexcept
+{
+  std::swap(serialization_support_, other.serialization_support_);
+  std::swap(rosidl_dynamic_type_, other.rosidl_dynamic_type_);
+  return *this;
+}
+
+
+DynamicMessageType::~DynamicMessageType() {}
+
+
+void
+DynamicMessageType::init_from_description(
+  const rosidl_runtime_c__type_description__TypeDescription & description,
+  DynamicSerializationSupport::SharedPtr serialization_support)
+{
+  if (serialization_support) {
+    // Swap serialization support if serialization support is given
+    serialization_support_ = serialization_support;
+  }
+
+  rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_create_from_description(
+    serialization_support_->get_rosidl_serialization_support(), &description, &rosidl_dynamic_type);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type) {
+    throw std::runtime_error("could not create new dynamic type object");
+  }
+
+  rosidl_dynamic_type_.reset(
+    rosidl_dynamic_type,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type)->void {
+      rosidl_dynamic_typesupport_dynamic_type_destroy(rosidl_dynamic_type);
+    });
+}
+
+
+bool
+DynamicMessageType::match_serialization_support_(
+  const DynamicSerializationSupport & serialization_support,
+  const rosidl_dynamic_typesupport_dynamic_type_t & rosidl_dynamic_type)
+{
+  bool out = true;
+
+  if (serialization_support.get_library_identifier() != std::string(
+      rosidl_dynamic_type.serialization_support->library_identifier))
+  {
+    RCUTILS_LOG_ERROR(
+      "serialization support library identifier does not match dynamic type's");
+    out = false;
+  }
+
+  // TODO(methylDragon): Can I do this?? Is it portable?
+  if (serialization_support.get_rosidl_serialization_support() !=
+    rosidl_dynamic_type.serialization_support)
+  {
+    RCUTILS_LOG_ERROR(
+      "serialization support pointer does not match dynamic type's");
+    out = false;
+  }
+
+  return out;
+}
+
+
+// GETTERS =========================================================================================
+const std::string
+DynamicMessageType::get_library_identifier() const
+{
+  return std::string(rosidl_dynamic_type_->serialization_support->library_identifier);
+}
+
+
+const std::string
+DynamicMessageType::get_name() const
+{
+  size_t buf_length;
+  const char * buf;
+  rosidl_dynamic_typesupport_dynamic_type_get_name(get_rosidl_dynamic_type(), &buf, &buf_length);
+  return std::string(buf, buf_length);
+}
+
+
+size_t
+DynamicMessageType::get_member_count() const
+{
+  size_t out;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_get_member_count(
+    rosidl_dynamic_type_.get(), &out);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error(
+            std::string("could not get member count: ") + rcl_get_error_string().str);
+  }
+  return out;
+}
+
+
+rosidl_dynamic_typesupport_dynamic_type_t *
+DynamicMessageType::get_rosidl_dynamic_type()
+{
+  return rosidl_dynamic_type_.get();
+}
+
+
+const rosidl_dynamic_typesupport_dynamic_type_t *
+DynamicMessageType::get_rosidl_dynamic_type() const
+{
+  return rosidl_dynamic_type_.get();
+}
+
+
+std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t>
+DynamicMessageType::get_shared_rosidl_dynamic_type()
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t>(
+    shared_from_this(), rosidl_dynamic_type_.get());
+}
+
+
+std::shared_ptr<const rosidl_dynamic_typesupport_dynamic_type_t>
+DynamicMessageType::get_shared_rosidl_dynamic_type() const
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_t>(
+    shared_from_this(), rosidl_dynamic_type_.get());
+}
+
+
+DynamicSerializationSupport::SharedPtr
+DynamicMessageType::get_shared_dynamic_serialization_support()
+{
+  return serialization_support_;
+}
+
+
+DynamicSerializationSupport::ConstSharedPtr
+DynamicMessageType::get_shared_dynamic_serialization_support() const
+{
+  return serialization_support_;
+}
+
+
+// METHODS =========================================================================================
+DynamicMessageType
+DynamicMessageType::clone() const
+{
+  rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_clone(
+    get_rosidl_dynamic_type(), &rosidl_dynamic_type);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type) {
+    throw std::runtime_error(
+            std::string("could not clone dynamic type: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessageType(serialization_support_, rosidl_dynamic_type);
+}
+
+
+DynamicMessageType::SharedPtr
+DynamicMessageType::clone_shared() const
+{
+  rosidl_dynamic_typesupport_dynamic_type_t * rosidl_dynamic_type = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_clone(
+    get_rosidl_dynamic_type(), &rosidl_dynamic_type);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type) {
+    throw std::runtime_error(
+            std::string("could not clone dynamic type: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessageType::make_shared(serialization_support_, rosidl_dynamic_type);
+}
+
+
+bool
+DynamicMessageType::equals(const DynamicMessageType & other) const
+{
+  if (get_library_identifier() != other.get_library_identifier()) {
+    throw std::runtime_error("library identifiers don't match");
+  }
+  bool out;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_equals(
+    get_rosidl_dynamic_type(), other.get_rosidl_dynamic_type(), &out);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error(
+            std::string("could not equate dynamic message types: ") + rcl_get_error_string().str);
+  }
+  return out;
+}
+
+
+DynamicMessage
+DynamicMessageType::build_dynamic_message()
+{
+  return DynamicMessage(shared_from_this());
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessageType::build_dynamic_message_shared()
+{
+  return DynamicMessage::make_shared(shared_from_this());
+}

rclcpp/src/rclcpp/dynamic_typesupport/dynamic_message_type_builder.cpp

@@ -0,0 +1,675 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <rosidl_dynamic_typesupport/api/dynamic_data.h>
+#include <rosidl_dynamic_typesupport/api/dynamic_type.h>
+#include <rosidl_dynamic_typesupport/types.h>
+
+#include <memory>
+#include <string>
+
+#include "rcutils/logging_macros.h"
+
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type_builder.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/exceptions.hpp"
+
+
+using rclcpp::dynamic_typesupport::DynamicMessage;
+using rclcpp::dynamic_typesupport::DynamicMessageType;
+using rclcpp::dynamic_typesupport::DynamicMessageTypeBuilder;
+using rclcpp::dynamic_typesupport::DynamicSerializationSupport;
+
+
+#ifndef RCLCPP__DYNAMIC_TYPESUPPORT__DETAIL__DYNAMIC_MESSAGE_TYPE_BUILDER_IMPL_HPP_
+// Template specialization implementations
+#include "rclcpp/dynamic_typesupport/detail/dynamic_message_type_builder_impl.hpp"
+#endif
+
+
+// CONSTRUCTION ====================================================================================
+DynamicMessageTypeBuilder::DynamicMessageTypeBuilder(
+  DynamicSerializationSupport::SharedPtr serialization_support, const std::string & name)
+: serialization_support_(serialization_support), rosidl_dynamic_type_builder_(nullptr)
+{
+  init_from_serialization_support_(serialization_support, name);
+  if (!rosidl_dynamic_type_builder_) {
+    throw std::runtime_error("could not create new dynamic type builder object");
+  }
+}
+
+
+DynamicMessageTypeBuilder::DynamicMessageTypeBuilder(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder)
+: serialization_support_(serialization_support), rosidl_dynamic_type_builder_(nullptr)
+{
+  if (!serialization_support) {
+    throw std::runtime_error("serialization support cannot be nullptr!");
+  }
+  if (!rosidl_dynamic_type_builder) {
+    throw std::runtime_error("rosidl dynamic type builder cannot be nullptr!");
+  }
+  if (!match_serialization_support_(*serialization_support, *rosidl_dynamic_type_builder)) {
+    throw std::runtime_error(
+            "serialization support library does not match dynamic type builder's!");
+  }
+
+  rosidl_dynamic_type_builder_.reset(
+    rosidl_dynamic_type_builder,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder)->void {
+      rosidl_dynamic_typesupport_dynamic_type_builder_destroy(rosidl_dynamic_type_builder);
+    });
+}
+
+
+DynamicMessageTypeBuilder::DynamicMessageTypeBuilder(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t> rosidl_dynamic_type_builder)
+: serialization_support_(serialization_support),
+  rosidl_dynamic_type_builder_(rosidl_dynamic_type_builder)
+{
+  if (!serialization_support) {
+    throw std::runtime_error("serialization support cannot be nullptr!");
+  }
+  if (!rosidl_dynamic_type_builder) {
+    throw std::runtime_error("rosidl dynamic type builder cannot be nullptr!");
+  }
+  if (!match_serialization_support_(*serialization_support, *rosidl_dynamic_type_builder.get())) {
+    throw std::runtime_error(
+            "serialization support library does not match dynamic type builder's!");
+  }
+}
+
+
+DynamicMessageTypeBuilder::DynamicMessageTypeBuilder(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  const rosidl_runtime_c__type_description__TypeDescription & description)
+: serialization_support_(serialization_support),
+  rosidl_dynamic_type_builder_(nullptr)
+{
+  if (!serialization_support) {
+    throw std::runtime_error("serialization support cannot be nullptr!");
+  }
+  init_from_description(description, serialization_support);
+}
+
+
+DynamicMessageTypeBuilder::DynamicMessageTypeBuilder(const DynamicMessageTypeBuilder & other)
+: enable_shared_from_this(), serialization_support_(nullptr), rosidl_dynamic_type_builder_(nullptr)
+{
+  DynamicMessageTypeBuilder out = other.clone();
+  std::swap(serialization_support_, out.serialization_support_);
+  std::swap(rosidl_dynamic_type_builder_, out.rosidl_dynamic_type_builder_);
+}
+
+
+DynamicMessageTypeBuilder::DynamicMessageTypeBuilder(DynamicMessageTypeBuilder && other) noexcept
+: serialization_support_(std::exchange(other.serialization_support_, nullptr)),
+  rosidl_dynamic_type_builder_(std::exchange(other.rosidl_dynamic_type_builder_, nullptr)) {}
+
+
+DynamicMessageTypeBuilder &
+DynamicMessageTypeBuilder::operator=(const DynamicMessageTypeBuilder & other)
+{
+  return *this = DynamicMessageTypeBuilder(other);
+}
+
+
+DynamicMessageTypeBuilder &
+DynamicMessageTypeBuilder::operator=(DynamicMessageTypeBuilder && other) noexcept
+{
+  std::swap(serialization_support_, other.serialization_support_);
+  std::swap(rosidl_dynamic_type_builder_, other.rosidl_dynamic_type_builder_);
+  return *this;
+}
+
+
+DynamicMessageTypeBuilder::~DynamicMessageTypeBuilder() {}
+
+
+void
+DynamicMessageTypeBuilder::init_from_description(
+  const rosidl_runtime_c__type_description__TypeDescription & description,
+  DynamicSerializationSupport::SharedPtr serialization_support)
+{
+  if (serialization_support) {
+    // Swap serialization support if serialization support is given
+    serialization_support_ = serialization_support;
+  }
+
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_builder_create_from_description(
+    serialization_support_->get_rosidl_serialization_support(), &description,
+    &rosidl_dynamic_type_builder);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type_builder) {
+    throw std::runtime_error("could not create new dynamic type builder object");
+  }
+
+  rosidl_dynamic_type_builder_.reset(
+    rosidl_dynamic_type_builder,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder)->void {
+      rosidl_dynamic_typesupport_dynamic_type_builder_destroy(rosidl_dynamic_type_builder);
+    });
+}
+
+
+void
+DynamicMessageTypeBuilder::init_from_serialization_support_(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  const std::string & name)
+{
+  if (!serialization_support) {
+    throw std::runtime_error("serialization support cannot be nullptr!");
+  }
+  if (!serialization_support->get_rosidl_serialization_support()) {
+    throw std::runtime_error("serialization support raw pointer cannot be nullptr!");
+  }
+
+
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_builder_create(
+    serialization_support->get_rosidl_serialization_support(),
+    name.c_str(), name.size(),
+    &rosidl_dynamic_type_builder);
+  if (ret != RCUTILS_RET_OK) {
+    throw std::runtime_error(
+            std::string("could not init dynamic type builder: ") + rcl_get_error_string().str);
+  }
+  if (!rosidl_dynamic_type_builder) {
+    throw std::runtime_error("could not init dynamic type builder object");
+  }
+
+  rosidl_dynamic_type_builder_.reset(
+    rosidl_dynamic_type_builder,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder)->void {
+      rosidl_dynamic_typesupport_dynamic_type_builder_destroy(rosidl_dynamic_type_builder);
+    });
+}
+
+
+bool
+DynamicMessageTypeBuilder::match_serialization_support_(
+  const DynamicSerializationSupport & serialization_support,
+  const rosidl_dynamic_typesupport_dynamic_type_builder_t & rosidl_dynamic_type_builder)
+{
+  bool out = true;
+
+  if (serialization_support.get_library_identifier() != std::string(
+      rosidl_dynamic_type_builder.serialization_support->library_identifier))
+  {
+    RCUTILS_LOG_ERROR(
+      "serialization support library identifier does not match dynamic type builder's");
+    out = false;
+  }
+
+  // TODO(methylDragon): Can I do this?? Is it portable?
+  if (serialization_support.get_rosidl_serialization_support() !=
+    rosidl_dynamic_type_builder.serialization_support)
+  {
+    RCUTILS_LOG_ERROR(
+      "serialization support pointer does not match dynamic type builder's");
+    out = false;
+  }
+
+  return out;
+}
+
+
+// GETTERS =======================================================================================
+const std::string
+DynamicMessageTypeBuilder::get_library_identifier() const
+{
+  return std::string(rosidl_dynamic_type_builder_->serialization_support->library_identifier);
+}
+
+
+const std::string
+DynamicMessageTypeBuilder::get_name() const
+{
+  size_t buf_length;
+  const char * buf;
+  rosidl_dynamic_typesupport_dynamic_type_builder_get_name(
+    get_rosidl_dynamic_type_builder(), &buf, &buf_length);
+  return std::string(buf, buf_length);
+}
+
+
+rosidl_dynamic_typesupport_dynamic_type_builder_t *
+DynamicMessageTypeBuilder::get_rosidl_dynamic_type_builder()
+{
+  return rosidl_dynamic_type_builder_.get();
+}
+
+
+const rosidl_dynamic_typesupport_dynamic_type_builder_t *
+DynamicMessageTypeBuilder::get_rosidl_dynamic_type_builder() const
+{
+  return rosidl_dynamic_type_builder_.get();
+}
+
+
+std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t>
+DynamicMessageTypeBuilder::get_shared_rosidl_dynamic_type_builder()
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t>(
+    shared_from_this(), rosidl_dynamic_type_builder_.get());
+}
+
+
+std::shared_ptr<const rosidl_dynamic_typesupport_dynamic_type_builder_t>
+DynamicMessageTypeBuilder::get_shared_rosidl_dynamic_type_builder() const
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_dynamic_type_builder_t>(
+    shared_from_this(), rosidl_dynamic_type_builder_.get());
+}
+
+
+DynamicSerializationSupport::SharedPtr
+DynamicMessageTypeBuilder::get_shared_dynamic_serialization_support()
+{
+  return serialization_support_;
+}
+
+
+DynamicSerializationSupport::ConstSharedPtr
+DynamicMessageTypeBuilder::get_shared_dynamic_serialization_support() const
+{
+  return serialization_support_;
+}
+
+
+// METHODS =======================================================================================
+void
+DynamicMessageTypeBuilder::set_name(const std::string & name)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_set_name(
+    get_rosidl_dynamic_type_builder(), name.c_str(), name.size());
+}
+
+
+DynamicMessageTypeBuilder
+DynamicMessageTypeBuilder::clone() const
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_builder_clone(
+    get_rosidl_dynamic_type_builder(), &rosidl_dynamic_type_builder);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type_builder) {
+    throw std::runtime_error(
+            std::string("could not clone dynamic type builder: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessageTypeBuilder(serialization_support_, rosidl_dynamic_type_builder);
+}
+
+
+DynamicMessageTypeBuilder::SharedPtr
+DynamicMessageTypeBuilder::clone_shared() const
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_t * rosidl_dynamic_type_builder = nullptr;
+  rcutils_ret_t ret = rosidl_dynamic_typesupport_dynamic_type_builder_clone(
+    get_rosidl_dynamic_type_builder(), &rosidl_dynamic_type_builder);
+  if (ret != RCUTILS_RET_OK || !rosidl_dynamic_type_builder) {
+    throw std::runtime_error(
+            std::string("could not clone dynamic type builder: ") + rcl_get_error_string().str);
+  }
+  return DynamicMessageTypeBuilder::make_shared(
+    serialization_support_, rosidl_dynamic_type_builder);
+}
+
+
+void
+DynamicMessageTypeBuilder::clear()
+{
+  if (!serialization_support_) {
+    throw std::runtime_error(
+            "cannot call clear() on a dynamic type builder with uninitialized serialization support"
+    );
+  }
+
+  const std::string & name = get_name();
+  init_from_serialization_support_(serialization_support_, name);
+  if (!rosidl_dynamic_type_builder_) {
+    throw std::runtime_error("could not create new dynamic type builder object");
+  }
+}
+
+
+DynamicMessage
+DynamicMessageTypeBuilder::build_dynamic_message()
+{
+  return DynamicMessage(shared_from_this());
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessageTypeBuilder::build_dynamic_message_shared()
+{
+  return DynamicMessage::make_shared(shared_from_this());
+}
+
+
+DynamicMessageType
+DynamicMessageTypeBuilder::build_dynamic_message_type()
+{
+  return DynamicMessageType(shared_from_this());
+}
+
+
+DynamicMessageType::SharedPtr
+DynamicMessageTypeBuilder::build_dynamic_message_type_shared()
+{
+  return DynamicMessageType::make_shared(shared_from_this());
+}
+
+
+// ADD MEMBERS =====================================================================================
+// Defined in "detail/dynamic_message_type_builder_impl.hpp"
+
+
+// ADD FIXED STRING MEMBERS ========================================================================
+void
+DynamicMessageTypeBuilder::add_fixed_string_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_length,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_string_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_wstring_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_length,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_wstring_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_string_array_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t string_length, size_t array_length, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_string_array_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_length, array_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_wstring_array_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t wstring_length, size_t array_length, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_wstring_array_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_length, array_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_string_unbounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_length,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_string_unbounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_wstring_unbounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_length,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_wstring_unbounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_string_bounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t string_length, size_t sequence_bound, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_string_bounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_length, sequence_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_fixed_wstring_bounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t wstring_length, size_t sequence_bound, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_fixed_wstring_bounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_length, sequence_bound);
+}
+
+
+// ADD BOUNDED STRING MEMBERS ======================================================================
+void
+DynamicMessageTypeBuilder::add_bounded_string_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_bound,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_string_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_wstring_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_bound,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_wstring_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_string_array_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t string_bound, size_t array_length, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_string_array_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_bound, array_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_wstring_array_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t wstring_bound, size_t array_length, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_wstring_array_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_bound, array_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_string_unbounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t string_bound,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_string_unbounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_wstring_unbounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name, size_t wstring_bound,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_wstring_unbounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_string_bounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t string_bound, size_t sequence_bound, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_string_bounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    string_bound, sequence_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_bounded_wstring_bounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  size_t wstring_bound, size_t sequence_bound, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_bounded_wstring_bounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    wstring_bound, sequence_bound);
+}
+
+
+// ADD NESTED MEMBERS ==============================================================================
+void
+DynamicMessageTypeBuilder::add_complex_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageType & nested_type, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type.get_rosidl_dynamic_type());
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_array_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageType & nested_type, size_t array_length, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_array_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type.get_rosidl_dynamic_type(), array_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_unbounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageType & nested_type, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_unbounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type.get_rosidl_dynamic_type());
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_bounded_sequence_member(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageType & nested_type, size_t sequence_bound, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_bounded_sequence_member(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type.get_rosidl_dynamic_type(), sequence_bound);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_member_builder(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageTypeBuilder & nested_type_builder, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_member_builder(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type_builder.get_rosidl_dynamic_type_builder());
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_array_member_builder(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageTypeBuilder & nested_type_builder, size_t array_length,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_array_member_builder(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type_builder.get_rosidl_dynamic_type_builder(), array_length);
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_unbounded_sequence_member_builder(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageTypeBuilder & nested_type_builder, const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_unbounded_sequence_member_builder(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type_builder.get_rosidl_dynamic_type_builder());
+}
+
+
+void
+DynamicMessageTypeBuilder::add_complex_bounded_sequence_member_builder(
+  rosidl_dynamic_typesupport_member_id_t id, const std::string & name,
+  DynamicMessageTypeBuilder & nested_type_builder, size_t sequence_bound,
+  const std::string & default_value)
+{
+  rosidl_dynamic_typesupport_dynamic_type_builder_add_complex_bounded_sequence_member_builder(
+    get_rosidl_dynamic_type_builder(),
+    id, name.c_str(), name.size(), default_value.c_str(), default_value.size(),
+    nested_type_builder.get_rosidl_dynamic_type_builder(), sequence_bound);
+}

rclcpp/src/rclcpp/dynamic_typesupport/dynamic_message_type_support.cpp

@@ -0,0 +1,465 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <rosidl_dynamic_typesupport/identifier.h>
+#include <rosidl_dynamic_typesupport/types.h>
+#include <rosidl_runtime_c/message_type_support_struct.h>
+#include <rosidl_runtime_c/type_description_utils.h>
+#include <rosidl_runtime_c/type_description/type_description__functions.h>
+#include <rosidl_runtime_c/type_description/type_description__struct.h>
+
+#include <memory>
+#include <string>
+
+#include "rcl/allocator.h"
+#include "rcl/dynamic_message_type_support.h"
+#include "rcl/type_hash.h"
+#include "rcl/types.h"
+#include "rcutils/logging_macros.h"
+#include "rcutils/types/rcutils_ret.h"
+#include "rmw/dynamic_message_type_support.h"
+
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_message_type_support.hpp"
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/exceptions.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+
+using rclcpp::dynamic_typesupport::DynamicMessage;
+using rclcpp::dynamic_typesupport::DynamicMessageType;
+using rclcpp::dynamic_typesupport::DynamicMessageTypeSupport;
+using rclcpp::dynamic_typesupport::DynamicSerializationSupport;
+
+
+// CONSTRUCTION ====================================================================================
+DynamicMessageTypeSupport::DynamicMessageTypeSupport(
+  const rosidl_runtime_c__type_description__TypeDescription & description,
+  const std::string & serialization_library_name)
+: serialization_support_(nullptr),
+  dynamic_message_type_(nullptr),
+  dynamic_message_(nullptr),
+  description_(nullptr),
+  rosidl_message_type_support_(nullptr)
+{
+  rosidl_message_type_support_t * ts = nullptr;
+  rcl_ret_t ret;
+
+  if (serialization_library_name.empty()) {
+    ret = rcl_dynamic_message_type_support_handle_create(nullptr, &description, &ts);
+  } else {
+    ret = rcl_dynamic_message_type_support_handle_create(
+      serialization_library_name.c_str(), &description, &ts);
+  }
+  if (ret != RCL_RET_OK) {
+    throw std::runtime_error("error initializing rosidl message type support");
+  }
+  if (!ts) {
+    throw std::runtime_error("could not init rosidl message type support");
+  }
+  if (!ts->data) {
+    throw std::runtime_error("could not init rosidl message type support impl");
+  }
+  if (ts->typesupport_identifier != rosidl_get_dynamic_typesupport_identifier()) {
+    throw std::runtime_error("rosidl message type support is of the wrong type");
+  }
+
+  // NOTE(methylDragon): Not technically const correct, but since it's a const void *,
+  //                     we do it anyway...
+  auto ts_impl = static_cast<const rosidl_dynamic_message_type_support_impl_t *>(ts->data);
+
+  // NOTE(methylDragon): We don't destroy the rosidl_message_type_support->data since its members
+  //                     are managed by the passed in SharedPtr wrapper classes. We just delete it.
+  rosidl_message_type_support_.reset(
+    ts,
+    [](rosidl_message_type_support_t * ts) -> void {
+      auto ts_impl = static_cast<const rosidl_dynamic_message_type_support_impl_t *>(ts->data);
+      auto allocator = rcl_get_default_allocator();
+
+      // These are all C allocated
+      allocator.deallocate(ts_impl->type_hash, &allocator.state);
+      allocator.deallocate(
+        const_cast<rosidl_dynamic_message_type_support_impl_t *>(ts_impl), &allocator.state);
+      allocator.deallocate(ts, &allocator.state);
+    }
+  );
+
+  manage_description_(ts_impl->type_description);
+  serialization_support_ = DynamicSerializationSupport::make_shared(ts_impl->serialization_support);
+
+  dynamic_message_type_ = DynamicMessageType::make_shared(
+    get_shared_dynamic_serialization_support(), ts_impl->dynamic_message_type);
+
+  dynamic_message_ = DynamicMessage::make_shared(
+    get_shared_dynamic_serialization_support(), ts_impl->dynamic_message);
+
+  if (!rosidl_message_type_support_) {
+    throw std::runtime_error("could not init rosidl message type support.");
+  }
+}
+
+
+DynamicMessageTypeSupport::DynamicMessageTypeSupport(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  const rosidl_runtime_c__type_description__TypeDescription & description)
+: serialization_support_(serialization_support),
+  dynamic_message_type_(nullptr),
+  dynamic_message_(nullptr),
+  description_(nullptr),
+  rosidl_message_type_support_(nullptr)
+{
+  // Check null
+  if (!serialization_support) {
+    throw std::runtime_error("serialization_support cannot be nullptr.");
+  }
+
+  rosidl_message_type_support_t * ts = nullptr;
+
+  auto type_hash = std::make_unique<rosidl_type_hash_t>();
+  rcutils_ret_t hash_ret = rcl_calculate_type_hash(
+    // TODO(methylDragon): Swap this out with the conversion function when it is ready
+    reinterpret_cast<const type_description_interfaces__msg__TypeDescription *>(&description),
+    type_hash.get());
+  if (hash_ret != RCL_RET_OK || !type_hash) {
+    throw std::runtime_error("failed to get type hash");
+  }
+
+  rcutils_ret_t ret = rosidl_dynamic_message_type_support_handle_create(
+    serialization_support->get_rosidl_serialization_support(),
+    type_hash.get(),  // type_hash
+    &description,     // type_description
+    nullptr,          // type_description_sources (not implemented for dynamic types)
+    &ts);
+  if (ret != RCUTILS_RET_OK || !ts) {
+    throw std::runtime_error("could not init rosidl message type support");
+  }
+  if (!ts->data) {
+    throw std::runtime_error("could not init rosidl message type support impl");
+  }
+  if (ts->typesupport_identifier != rosidl_get_dynamic_typesupport_identifier()) {
+    throw std::runtime_error("rosidl message type support is of the wrong type");
+  }
+
+  auto ts_impl = static_cast<const rosidl_dynamic_message_type_support_impl_t *>(ts->data);
+
+  // NOTE(methylDragon): We don't finalize the rosidl_message_type_support->data since its members
+  //                     are managed by the passed in SharedPtr wrapper classes. We just delete it.
+  rosidl_message_type_support_.reset(
+    ts,
+    [](rosidl_message_type_support_t * ts) -> void {
+      auto ts_impl = static_cast<const rosidl_dynamic_message_type_support_impl_t *>(ts->data);
+
+      // These are allocated with new
+      delete ts_impl->type_hash;  // Only because we should've allocated it here
+      delete ts_impl;
+      delete ts;
+    }
+  );
+  manage_description_(ts_impl->type_description);
+
+  dynamic_message_type_ = DynamicMessageType::make_shared(
+    get_shared_dynamic_serialization_support(), ts_impl->dynamic_message_type);
+
+  dynamic_message_ = DynamicMessage::make_shared(
+    get_shared_dynamic_serialization_support(), ts_impl->dynamic_message);
+
+  if (!rosidl_message_type_support_) {
+    throw std::runtime_error("could not init rosidl message type support.");
+  }
+
+  type_hash.release();
+}
+
+
+DynamicMessageTypeSupport::DynamicMessageTypeSupport(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  DynamicMessageType::SharedPtr dynamic_message_type,
+  DynamicMessage::SharedPtr dynamic_message,
+  const rosidl_runtime_c__type_description__TypeDescription & description)
+: serialization_support_(serialization_support),
+  dynamic_message_type_(dynamic_message_type),
+  dynamic_message_(dynamic_message),
+  description_(nullptr),
+  rosidl_message_type_support_(nullptr)
+{
+  // Check null
+  if (!serialization_support) {
+    throw std::runtime_error("serialization_support cannot be nullptr.");
+  }
+  if (!dynamic_message_type) {
+    throw std::runtime_error("dynamic_message_type cannot be nullptr.");
+  }
+  if (!dynamic_message) {
+    throw std::runtime_error("dynamic_message cannot be nullptr.");
+  }
+
+  description_.reset(
+    new rosidl_runtime_c__type_description__TypeDescription(),
+    [](rosidl_runtime_c__type_description__TypeDescription * description) -> void {
+      rosidl_runtime_c__type_description__TypeDescription__destroy(description);
+    });
+  if (!description_) {
+    throw std::runtime_error("could not init type description.");
+  }
+  if (!rosidl_runtime_c__type_description__TypeDescription__copy(
+      &description,
+      description_.get()))
+  {
+    throw std::runtime_error("could not copy type description.");
+  }
+
+  // Check identifiers
+  if (serialization_support->get_library_identifier() !=
+    dynamic_message_type->get_library_identifier())
+  {
+    throw std::runtime_error(
+            "serialization support library identifier does not match "
+            "dynamic message type library identifier.");
+  }
+  if (dynamic_message_type->get_library_identifier() != dynamic_message->get_library_identifier()) {
+    throw std::runtime_error(
+            "dynamic message type library identifier does not match "
+            "dynamic message library identifier.");
+  }
+
+  // Check pointers
+  /* *INDENT-OFF* */
+  if (serialization_support->get_rosidl_serialization_support() !=
+      dynamic_message_type
+        ->get_shared_dynamic_serialization_support()
+        ->get_rosidl_serialization_support())
+  {
+    throw std::runtime_error("serialization support pointer does not match dynamic message type's");
+  }
+  if (dynamic_message_type
+        ->get_shared_dynamic_serialization_support()
+        ->get_rosidl_serialization_support() !=
+      dynamic_message_type
+        ->get_shared_dynamic_serialization_support()
+        ->get_rosidl_serialization_support())
+  {
+    throw std::runtime_error("serialization support does not match pointer dynamic message type's");
+  }
+  /* *INDENT-ON* */
+
+  init_rosidl_message_type_support_(
+    serialization_support_, dynamic_message_type_, dynamic_message_, description_.get());
+  if (!rosidl_message_type_support_) {
+    throw std::runtime_error("could not init rosidl message type support.");
+  }
+}
+
+
+DynamicMessageTypeSupport::~DynamicMessageTypeSupport() {}
+
+
+void
+DynamicMessageTypeSupport::manage_description_(
+  rosidl_runtime_c__type_description__TypeDescription * description)
+{
+  if (!description) {
+    throw std::runtime_error("description cannot be nullptr");
+  }
+  description_.reset(
+    description,
+    [](rosidl_runtime_c__type_description__TypeDescription * description) -> void {
+      rosidl_runtime_c__type_description__TypeDescription__destroy(description);
+    });
+}
+
+
+// This looks like rmw_`dynamic_message_type_support_handle_create()`, but instead just aggregates
+// already initialized objects
+void
+DynamicMessageTypeSupport::init_rosidl_message_type_support_(
+  DynamicSerializationSupport::SharedPtr serialization_support,
+  DynamicMessageType::SharedPtr dynamic_message_type,
+  DynamicMessage::SharedPtr dynamic_message,
+  rosidl_runtime_c__type_description__TypeDescription * description)
+{
+  bool middleware_supports_type_discovery = rmw_feature_supported(
+    RMW_MIDDLEWARE_SUPPORTS_TYPE_DISCOVERY);
+
+  if (!middleware_supports_type_discovery && !description) {
+    throw std::runtime_error(
+            "Middleware does not support type discovery! Deferred dynamic type"
+            "message type support will never be populated! You must provide a type "
+            "description.");
+    return;
+  }
+
+  auto type_hash = std::make_unique<rosidl_type_hash_t>();
+  rcutils_ret_t hash_ret = rcl_calculate_type_hash(
+    // TODO(methylDragon): Swap this out with the conversion function when it is ready
+    //   from https://github.com/ros2/rcl/pull/1052
+    reinterpret_cast<type_description_interfaces__msg__TypeDescription *>(description),
+    type_hash.get());
+  if (hash_ret != RCL_RET_OK || !type_hash) {
+    throw std::runtime_error("failed to get type hash");
+  }
+
+  rosidl_dynamic_message_type_support_impl_t * ts_impl =
+    new rosidl_dynamic_message_type_support_impl_t {
+    type_hash.get(),                                              // type_hash
+    description,                                                  // type_description
+    nullptr,    // NOTE(methylDragon): Not supported for now      // type_description_sources
+    serialization_support->get_rosidl_serialization_support(),    // serialization_support
+    dynamic_message_type->get_rosidl_dynamic_type(),              // dynamic_message_type
+    dynamic_message->get_rosidl_dynamic_data()                    // dynamic_message
+  };
+  if (!ts_impl) {
+    throw std::runtime_error(
+            "Could not allocate rosidl_dynamic_message_type_support_impl_t struct");
+    return;
+  }
+
+  // NOTE(methylDragon): We don't finalize the rosidl_message_type_support->data since its members
+  //                     are managed by the passed in SharedPtr wrapper classes. We just delete it.
+  rosidl_message_type_support_.reset(
+    new rosidl_message_type_support_t{
+    rosidl_get_dynamic_typesupport_identifier(),          // typesupport_identifier
+    ts_impl,                                              // data
+    get_message_typesupport_handle_function,              // func
+    // get_type_hash_func
+    rosidl_get_dynamic_message_type_support_type_hash_function,
+    // get_type_description_func
+    rosidl_get_dynamic_message_type_support_type_description_function,
+    // get_type_description_sources_func
+    rosidl_get_dynamic_message_type_support_type_description_sources_function
+  },
+    [](rosidl_message_type_support_t * ts) -> void {
+      auto ts_impl = static_cast<const rosidl_dynamic_message_type_support_impl_t *>(ts->data);
+      auto allocator = rcl_get_default_allocator();
+      // Only because we should've allocated it here (also it's C allocated)
+      allocator.deallocate(ts_impl->type_hash, &allocator.state);
+      delete ts_impl;
+    }
+  );
+
+  if (!rosidl_message_type_support_) {
+    throw std::runtime_error("Could not allocate rosidl_message_type_support_t struct");
+    delete ts_impl;
+    return;
+  }
+
+  type_hash.release();
+}
+
+
+// GETTERS =========================================================================================
+const std::string
+DynamicMessageTypeSupport::get_library_identifier() const
+{
+  return serialization_support_->get_library_identifier();
+}
+
+
+rosidl_message_type_support_t *
+DynamicMessageTypeSupport::get_rosidl_message_type_support()
+{
+  return rosidl_message_type_support_.get();
+}
+
+
+const rosidl_message_type_support_t *
+DynamicMessageTypeSupport::get_rosidl_message_type_support() const
+{
+  return rosidl_message_type_support_.get();
+}
+
+
+std::shared_ptr<rosidl_message_type_support_t>
+DynamicMessageTypeSupport::get_shared_rosidl_message_type_support()
+{
+  return rosidl_message_type_support_;
+}
+
+
+std::shared_ptr<const rosidl_message_type_support_t>
+DynamicMessageTypeSupport::get_shared_rosidl_message_type_support() const
+{
+  return rosidl_message_type_support_;
+}
+
+
+rosidl_runtime_c__type_description__TypeDescription *
+DynamicMessageTypeSupport::get_rosidl_runtime_c_type_description()
+{
+  return description_.get();
+}
+
+
+const rosidl_runtime_c__type_description__TypeDescription *
+DynamicMessageTypeSupport::get_rosidl_runtime_c_type_description() const
+{
+  return description_.get();
+}
+
+
+std::shared_ptr<rosidl_runtime_c__type_description__TypeDescription>
+DynamicMessageTypeSupport::get_shared_rosidl_runtime_c_type_description()
+{
+  return description_;
+}
+
+
+std::shared_ptr<const rosidl_runtime_c__type_description__TypeDescription>
+DynamicMessageTypeSupport::get_shared_rosidl_runtime_c_type_description() const
+{
+  return description_;
+}
+
+
+DynamicSerializationSupport::SharedPtr
+DynamicMessageTypeSupport::get_shared_dynamic_serialization_support()
+{
+  return serialization_support_;
+}
+
+
+DynamicSerializationSupport::ConstSharedPtr
+DynamicMessageTypeSupport::get_shared_dynamic_serialization_support() const
+{
+  return serialization_support_;
+}
+
+
+DynamicMessageType::SharedPtr
+DynamicMessageTypeSupport::get_shared_dynamic_message_type()
+{
+  return dynamic_message_type_;
+}
+
+
+DynamicMessageType::ConstSharedPtr
+DynamicMessageTypeSupport::get_shared_dynamic_message_type() const
+{
+  return dynamic_message_type_;
+}
+
+
+DynamicMessage::SharedPtr
+DynamicMessageTypeSupport::get_shared_dynamic_message()
+{
+  return dynamic_message_;
+}
+
+
+DynamicMessage::ConstSharedPtr
+DynamicMessageTypeSupport::get_shared_dynamic_message() const
+{
+  return dynamic_message_;
+}

rclcpp/src/rclcpp/dynamic_typesupport/dynamic_serialization_support.cpp

@@ -0,0 +1,136 @@
+// Copyright 2023 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <rosidl_dynamic_typesupport/api/serialization_support.h>
+
+#include <memory>
+#include <string>
+
+#include "rcutils/logging_macros.h"
+#include "rmw/dynamic_message_type_support.h"
+#include "rmw/ret_types.h"
+
+#include "rclcpp/dynamic_typesupport/dynamic_serialization_support.hpp"
+#include "rclcpp/exceptions.hpp"
+
+
+using rclcpp::dynamic_typesupport::DynamicSerializationSupport;
+
+// CONSTRUCTION ====================================================================================
+DynamicSerializationSupport::DynamicSerializationSupport()
+: DynamicSerializationSupport::DynamicSerializationSupport("") {}
+
+DynamicSerializationSupport::DynamicSerializationSupport(
+  const std::string & serialization_library_name)
+: rosidl_serialization_support_(nullptr)
+{
+  rosidl_dynamic_typesupport_serialization_support_t * rosidl_serialization_support = nullptr;
+  rmw_ret_t ret = RMW_RET_ERROR;
+
+  if (serialization_library_name.empty()) {
+    ret = rmw_get_serialization_support(NULL, &rosidl_serialization_support);
+  } else {
+    ret = rmw_get_serialization_support(
+      serialization_library_name.c_str(), &rosidl_serialization_support);
+  }
+
+  if (ret != RMW_RET_OK || !rosidl_serialization_support) {
+    throw std::runtime_error("could not create new serialization support object");
+  }
+
+  rosidl_serialization_support_.reset(
+    rosidl_serialization_support,
+    // Custom deleter
+    [](rosidl_dynamic_typesupport_serialization_support_t * rosidl_serialization_support) -> void {
+      rosidl_dynamic_typesupport_serialization_support_destroy(rosidl_serialization_support);
+    });
+}
+
+
+DynamicSerializationSupport::DynamicSerializationSupport(
+  rosidl_dynamic_typesupport_serialization_support_t * rosidl_serialization_support)
+: rosidl_serialization_support_(nullptr)
+{
+  if (!rosidl_serialization_support) {
+    throw std::runtime_error("serialization support cannot be nullptr!");
+  }
+
+  // Custom deleter
+  rosidl_serialization_support_.reset(
+    rosidl_serialization_support,
+    [](rosidl_dynamic_typesupport_serialization_support_t * rosidl_serialization_support) -> void {
+      rosidl_dynamic_typesupport_serialization_support_destroy(rosidl_serialization_support);
+    });
+}
+
+
+DynamicSerializationSupport::DynamicSerializationSupport(
+  std::shared_ptr<rosidl_dynamic_typesupport_serialization_support_t> rosidl_serialization_support)
+: rosidl_serialization_support_(rosidl_serialization_support) {}
+
+
+DynamicSerializationSupport::DynamicSerializationSupport(
+  DynamicSerializationSupport && other) noexcept
+: rosidl_serialization_support_(std::exchange(other.rosidl_serialization_support_, nullptr)) {}
+
+
+DynamicSerializationSupport &
+DynamicSerializationSupport::operator=(DynamicSerializationSupport && other) noexcept
+{
+  std::swap(rosidl_serialization_support_, other.rosidl_serialization_support_);
+  return *this;
+}
+
+
+DynamicSerializationSupport::~DynamicSerializationSupport() {}
+
+
+// GETTERS =========================================================================================
+const std::string
+DynamicSerializationSupport::get_library_identifier() const
+{
+  return std::string(
+    rosidl_dynamic_typesupport_serialization_support_get_library_identifier(
+      rosidl_serialization_support_.get()));
+}
+
+
+rosidl_dynamic_typesupport_serialization_support_t *
+DynamicSerializationSupport::get_rosidl_serialization_support()
+{
+  return rosidl_serialization_support_.get();
+}
+
+
+const rosidl_dynamic_typesupport_serialization_support_t *
+DynamicSerializationSupport::get_rosidl_serialization_support() const
+{
+  return rosidl_serialization_support_.get();
+}
+
+
+std::shared_ptr<rosidl_dynamic_typesupport_serialization_support_t>
+DynamicSerializationSupport::get_shared_rosidl_serialization_support()
+{
+  return std::shared_ptr<rosidl_dynamic_typesupport_serialization_support_t>(
+    shared_from_this(), rosidl_serialization_support_.get());
+}
+
+
+std::shared_ptr<const rosidl_dynamic_typesupport_serialization_support_t>
+DynamicSerializationSupport::get_shared_rosidl_serialization_support() const
+{
+  return std::shared_ptr<const rosidl_dynamic_typesupport_serialization_support_t>(
+    shared_from_this(), rosidl_serialization_support_.get());
+}

rclcpp/src/rclcpp/executor.cpp

@@ -24,6 +24,7 @@
 #include "rcl/error_handling.h"
 #include "rcpputils/scope_exit.hpp"
 
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
 #include "rclcpp/exceptions.hpp"
 #include "rclcpp/executor.hpp"
 #include "rclcpp/guard_condition.hpp"
@@ -598,70 +599,136 @@ take_and_do_error_handling(
 void
 Executor::execute_subscription(rclcpp::SubscriptionBase::SharedPtr subscription)
 {
+  using rclcpp::dynamic_typesupport::DynamicMessage;
+
   rclcpp::MessageInfo message_info;
   message_info.get_rmw_message_info().from_intra_process = false;
 
-  if (subscription->is_serialized()) {
-    // This is the case where a copy of the serialized message is taken from
-    // the middleware via inter-process communication.
-    std::shared_ptr<SerializedMessage> serialized_msg = subscription->create_serialized_message();
-    take_and_do_error_handling(
-      "taking a serialized message from topic",
-      subscription->get_topic_name(),
-      [&]() {return subscription->take_serialized(*serialized_msg.get(), message_info);},
-      [&]()
+  switch (subscription->get_subscription_type()) {
+    // Take ROS message
+    case rclcpp::SubscriptionType::ROS_MESSAGE:
       {
-        subscription->handle_serialized_message(serialized_msg, message_info);
-      });
-    subscription->return_serialized_message(serialized_msg);
-  } else if (subscription->can_loan_messages()) {
-    // This is the case where a loaned message is taken from the middleware via
-    // inter-process communication, given to the user for their callback,
-    // and then returned.
-    void * loaned_msg = nullptr;
-    // TODO(wjwwood): refactor this into methods on subscription when LoanedMessage
-    //   is extened to support subscriptions as well.
-    take_and_do_error_handling(
-      "taking a loaned message from topic",
-      subscription->get_topic_name(),
-      [&]()
-      {
-        rcl_ret_t ret = rcl_take_loaned_message(
-          subscription->get_subscription_handle().get(),
-          &loaned_msg,
-          &message_info.get_rmw_message_info(),
-          nullptr);
-        if (RCL_RET_SUBSCRIPTION_TAKE_FAILED == ret) {
-          return false;
-        } else if (RCL_RET_OK != ret) {
-          rclcpp::exceptions::throw_from_rcl_error(ret);
+        if (subscription->can_loan_messages()) {
+          // This is the case where a loaned message is taken from the middleware via
+          // inter-process communication, given to the user for their callback,
+          // and then returned.
+          void * loaned_msg = nullptr;
+          // TODO(wjwwood): refactor this into methods on subscription when LoanedMessage
+          //   is extened to support subscriptions as well.
+          take_and_do_error_handling(
+            "taking a loaned message from topic",
+            subscription->get_topic_name(),
+            [&]()
+            {
+              rcl_ret_t ret = rcl_take_loaned_message(
+                subscription->get_subscription_handle().get(),
+                &loaned_msg,
+                &message_info.get_rmw_message_info(),
+                nullptr);
+              if (RCL_RET_SUBSCRIPTION_TAKE_FAILED == ret) {
+                return false;
+              } else if (RCL_RET_OK != ret) {
+                rclcpp::exceptions::throw_from_rcl_error(ret);
+              }
+              return true;
+            },
+            [&]() {subscription->handle_loaned_message(loaned_msg, message_info);});
+          if (nullptr != loaned_msg) {
+            rcl_ret_t ret = rcl_return_loaned_message_from_subscription(
+              subscription->get_subscription_handle().get(), loaned_msg);
+            if (RCL_RET_OK != ret) {
+              RCLCPP_ERROR(
+                rclcpp::get_logger("rclcpp"),
+                "rcl_return_loaned_message_from_subscription() failed for subscription on topic "
+                "'%s': %s",
+                subscription->get_topic_name(), rcl_get_error_string().str);
+            }
+            loaned_msg = nullptr;
+          }
+        } else {
+          // This case is taking a copy of the message data from the middleware via
+          // inter-process communication.
+          std::shared_ptr<void> message = subscription->create_message();
+          take_and_do_error_handling(
+            "taking a message from topic",
+            subscription->get_topic_name(),
+            [&]() {return subscription->take_type_erased(message.get(), message_info);},
+            [&]() {subscription->handle_message(message, message_info);});
+          subscription->return_message(message);
         }
-        return true;
-      },
-      [&]() {subscription->handle_loaned_message(loaned_msg, message_info);});
-    if (nullptr != loaned_msg) {
-      rcl_ret_t ret = rcl_return_loaned_message_from_subscription(
-        subscription->get_subscription_handle().get(),
-        loaned_msg);
-      if (RCL_RET_OK != ret) {
-        RCLCPP_ERROR(
-          rclcpp::get_logger("rclcpp"),
-          "rcl_return_loaned_message_from_subscription() failed for subscription on topic '%s': %s",
-          subscription->get_topic_name(), rcl_get_error_string().str);
+        break;
+      }
+
+    // Take serialized message
+    case rclcpp::SubscriptionType::SERIALIZED_MESSAGE:
+      {
+        // This is the case where a copy of the serialized message is taken from
+        // the middleware via inter-process communication.
+        std::shared_ptr<SerializedMessage> serialized_msg =
+          subscription->create_serialized_message();
+        take_and_do_error_handling(
+          "taking a serialized message from topic",
+          subscription->get_topic_name(),
+          [&]() {return subscription->take_serialized(*serialized_msg.get(), message_info);},
+          [&]()
+          {
+            subscription->handle_serialized_message(serialized_msg, message_info);
+          });
+        subscription->return_serialized_message(serialized_msg);
+        break;
+      }
+
+    // DYNAMIC SUBSCRIPTION ========================================================================
+    // If a subscription is dynamic, then it will use its serialization-specific dynamic data.
+    //
+    // Two cases:
+    // - Dynamic type subscription using dynamic type stored in its own internal type support struct
+    // - Non-dynamic type subscription with no stored dynamic type
+    //   - Subscriptions of this type must be able to lookup the local message description to
+    //     generate a dynamic type at runtime!
+    //   - TODO(methylDragon): I won't be handling this case yet
+
+    // Take dynamic message directly from the middleware
+    case rclcpp::SubscriptionType::DYNAMIC_MESSAGE_DIRECT:
+      {
+        DynamicMessage::SharedPtr dynamic_message = subscription->create_dynamic_message();
+        take_and_do_error_handling(
+          "taking a dynamic message from topic",
+          subscription->get_topic_name(),
+          // This modifies the stored dynamic data in the DynamicMessage in-place
+          [&]() {return subscription->take_dynamic_message(*dynamic_message, message_info);},
+          [&]() {subscription->handle_dynamic_message(dynamic_message, message_info);});
+        subscription->return_dynamic_message(dynamic_message);
+        break;
+      }
+
+    // Take serialized and then convert to dynamic message
+    case rclcpp::SubscriptionType::DYNAMIC_MESSAGE_FROM_SERIALIZED:
+      {
+        std::shared_ptr<SerializedMessage> serialized_msg =
+          subscription->create_serialized_message();
+
+        // NOTE(methylDragon): Is this clone necessary? If I'm following the pattern, it seems so.
+        DynamicMessage::SharedPtr dynamic_message = subscription->create_dynamic_message();
+        take_and_do_error_handling(
+          "taking a serialized message from topic",
+          subscription->get_topic_name(),
+          [&]() {return subscription->take_serialized(*serialized_msg.get(), message_info);},
+          [&]()
+          {
+            bool ret = dynamic_message->deserialize(&serialized_msg->get_rcl_serialized_message());
+            if (!ret) {
+              throw_from_rcl_error(ret, "Couldn't convert serialized message to dynamic data!");
+            }
+            subscription->handle_dynamic_message(dynamic_message, message_info);
+          }
+        );
+        subscription->return_serialized_message(serialized_msg);
+        subscription->return_dynamic_message(dynamic_message);
+        break;
       }
-      loaned_msg = nullptr;
-    }
-  } else {
-    // This case is taking a copy of the message data from the middleware via
-    // inter-process communication.
-    std::shared_ptr<void> message = subscription->create_message();
-    take_and_do_error_handling(
-      "taking a message from topic",
-      subscription->get_topic_name(),
-      [&]() {return subscription->take_type_erased(message.get(), message_info);},
-      [&]() {subscription->handle_message(message, message_info);});
-    subscription->return_message(message);
   }
+  return;
 }
 
 void

rclcpp/src/rclcpp/generic_subscription.cpp

@@ -43,8 +43,7 @@ void GenericSubscription::handle_message(
           "handle_message is not implemented for GenericSubscription");
 }
 
-void
-GenericSubscription::handle_serialized_message(
+void GenericSubscription::handle_serialized_message(
   const std::shared_ptr<rclcpp::SerializedMessage> & message,
   const rclcpp::MessageInfo &)
 {
@@ -72,4 +71,55 @@ void GenericSubscription::return_serialized_message(
   message.reset();
 }
 
+
+// DYNAMIC TYPE ====================================================================================
+// TODO(methylDragon): Reorder later
+rclcpp::dynamic_typesupport::DynamicMessageType::SharedPtr
+GenericSubscription::get_shared_dynamic_message_type()
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "get_shared_dynamic_message_type is not implemented for GenericSubscription");
+}
+
+rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+GenericSubscription::get_shared_dynamic_message()
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "get_shared_dynamic_message is not implemented for GenericSubscription");
+}
+
+rclcpp::dynamic_typesupport::DynamicSerializationSupport::SharedPtr
+GenericSubscription::get_shared_dynamic_serialization_support()
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "get_shared_dynamic_serialization_support is not implemented for GenericSubscription");
+}
+
+rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr
+GenericSubscription::create_dynamic_message()
+{
+  throw rclcpp::exceptions::UnimplementedError(
+          "create_dynamic_message is not implemented for GenericSubscription");
+}
+
+void
+GenericSubscription::return_dynamic_message(
+  rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message)
+{
+  (void) message;
+  throw rclcpp::exceptions::UnimplementedError(
+          "return_dynamic_message is not implemented for GenericSubscription");
+}
+
+void
+GenericSubscription::handle_dynamic_message(
+  const rclcpp::dynamic_typesupport::DynamicMessage::SharedPtr & message,
+  const rclcpp::MessageInfo & message_info)
+{
+  (void) message;
+  (void) message_info;
+  throw rclcpp::exceptions::UnimplementedError(
+          "handle_dynamic_message is not implemented for GenericSubscription");
+}
+
 }  // namespace rclcpp

rclcpp/src/rclcpp/subscription_base.cpp

@@ -22,6 +22,7 @@
 
 #include "rcpputils/scope_exit.hpp"
 
+#include "rclcpp/dynamic_typesupport/dynamic_message.hpp"
 #include "rclcpp/exceptions.hpp"
 #include "rclcpp/expand_topic_or_service_name.hpp"
 #include "rclcpp/experimental/intra_process_manager.hpp"
@@ -32,6 +33,8 @@
 #include "rmw/error_handling.h"
 #include "rmw/rmw.h"
 
+#include "rosidl_dynamic_typesupport/types.h"
+
 using rclcpp::SubscriptionBase;
 
 SubscriptionBase::SubscriptionBase(
@@ -41,7 +44,7 @@ SubscriptionBase::SubscriptionBase(
   const rcl_subscription_options_t & subscription_options,
   const SubscriptionEventCallbacks & event_callbacks,
   bool use_default_callbacks,
-  bool is_serialized)
+  SubscriptionType subscription_type)
 : node_base_(node_base),
   node_handle_(node_base_->get_shared_rcl_node_handle()),
   node_logger_(rclcpp::get_node_logger(node_handle_.get())),
@@ -49,8 +52,16 @@ SubscriptionBase::SubscriptionBase(
   intra_process_subscription_id_(0),
   event_callbacks_(event_callbacks),
   type_support_(type_support_handle),
-  is_serialized_(is_serialized)
+  subscription_type_(subscription_type)
 {
+  if (!rmw_feature_supported(RMW_MIDDLEWARE_CAN_TAKE_DYNAMIC_MESSAGE) &&
+    subscription_type == rclcpp::SubscriptionType::DYNAMIC_MESSAGE_DIRECT)
+  {
+    throw std::runtime_error(
+            "Cannot set subscription to take dynamic message directly, feature not supported in rmw"
+    );
+  }
+
   auto custom_deletor = [node_handle = this->node_handle_](rcl_subscription_t * rcl_subs)
     {
       if (rcl_subscription_fini(rcl_subs, node_handle.get()) != RCL_RET_OK) {
@@ -255,10 +266,10 @@ SubscriptionBase::get_message_type_support_handle() const
   return type_support_;
 }
 
-bool
-SubscriptionBase::is_serialized() const
+rclcpp::SubscriptionType
+SubscriptionBase::get_subscription_type() const
 {
-  return is_serialized_;
+  return subscription_type_;
 }
 
 size_t
@@ -442,8 +453,7 @@ SubscriptionBase::set_content_filter(
   rcl_subscription_content_filter_options_t options =
     rcl_get_zero_initialized_subscription_content_filter_options();
 
-  std::vector<const char *> cstrings =
-    get_c_vector_string(expression_parameters);
+  std::vector<const char *> cstrings = get_c_vector_string(expression_parameters);
   rcl_ret_t ret = rcl_subscription_content_filter_options_init(
     subscription_handle_.get(),
     get_c_string(filter_expression),
@@ -515,3 +525,24 @@ SubscriptionBase::get_content_filter() const
 
   return ret_options;
 }
+
+
+// DYNAMIC TYPE ==================================================================================
+// TODO(methylDragon): Reorder later
+bool
+SubscriptionBase::take_dynamic_message(
+  rclcpp::dynamic_typesupport::DynamicMessage & message_out,
+  rclcpp::MessageInfo & message_info_out)
+{
+  rcl_ret_t ret = rcl_take_dynamic_message(
+    this->get_subscription_handle().get(),
+    message_out.get_rosidl_dynamic_data(),
+    &message_info_out.get_rmw_message_info(),
+    nullptr);
+  if (RCL_RET_SUBSCRIPTION_TAKE_FAILED == ret) {
+    return false;
+  } else if (RCL_RET_OK != ret) {
+    rclcpp::exceptions::throw_from_rcl_error(ret);
+  }
+  return true;
+}

rclcpp/test/rclcpp/node_interfaces/test_node_topics.cpp

@@ -28,6 +28,11 @@
 #include "../../mocking_utils/patch.hpp"
 #include "../../utils/rclcpp_gtest_macros.hpp"
 
+using rclcpp::dynamic_typesupport::DynamicMessage;
+using rclcpp::dynamic_typesupport::DynamicMessageType;
+using rclcpp::dynamic_typesupport::DynamicSerializationSupport;
+
+
 namespace
 {
 
@@ -77,6 +82,18 @@ public:
     const std::shared_ptr<rclcpp::SerializedMessage> &, const rclcpp::MessageInfo &) override {}
   void return_message(std::shared_ptr<void> &) override {}
   void return_serialized_message(std::shared_ptr<rclcpp::SerializedMessage> &) override {}
+
+  DynamicMessageType::SharedPtr get_shared_dynamic_message_type() override {return nullptr;}
+  DynamicMessage::SharedPtr get_shared_dynamic_message() override {return nullptr;}
+  DynamicSerializationSupport::SharedPtr get_shared_dynamic_serialization_support() override
+  {
+    return nullptr;
+  }
+  DynamicMessage::SharedPtr create_dynamic_message() override {return nullptr;}
+  void return_dynamic_message(DynamicMessage::SharedPtr &) override {}
+  void handle_dynamic_message(
+    const DynamicMessage::SharedPtr &,
+    const rclcpp::MessageInfo &) override {}
 };
 
 class TestNodeTopics : public ::testing::Test

rclcpp/test/rclcpp/test_generic_pubsub.cpp

@@ -89,9 +89,9 @@ public:
     T2 message;
     write_message(data, message);
 
-    rclcpp::Serialization<T2> ser;
+    rclcpp::Serialization<T2> serialization_support;
     SerializedMessage result;
-    ser.serialize_message(&message, &result);
+    serialization_support.serialize_message(&message, &result);
     return result;
   }